博士（体育科学）, 筑波大学

Ph.D, University of Tsukuba

bio-imaging

skeletal muscle

Life sciences, Physiology

Life sciences, Sports science

01 Apr. 2012
University of Electro-Communications, Professor

01 Apr. 2005 - 31 Mar. 2012
電気通信大学, 助教授，准教授

Sep. 1997 - Mar. 2005
電気通信大学, 講師

Mar. 1997
University of Tsukuba, Graduate School, Division of Physical Fitness and Science, 体育学専攻

Mar. 1992
Gunma University, Faculty of Education, 保健体育学科

01 Apr. 1985 - 31 Mar. 1988
前橋育英高等学校

Sep. 2023 - Present
The Journal of Physiological Sciences, Editor, Physiological Society of Japan, Society

2005
評議員, 日本運動生理学会, Society

2001 - 2003
編集委員, トレーニング科学会, Society

1998 - 2003
編集幹事, 日本体育学会, Society

2000
評議員, 日本体力医学会, Society

Time-series transcriptomics reveals distinctive mRNA expression dynamics associated with gene ontology specificity and protein expression in skeletal muscle after electrical stimulation-induced resistance exercise.
Tatsuya Kusano; Yuta Sotani; Reo Takeda; Atsushi Hatano; Kentaro Kawata; Ryotaro Kano; Masaki Matsumoto; Yutaka Kano; Daisuke Hoshino
FASEB journal : Official publication of the federation of american societies for experimental biology, 38, 22, e70153, 30 Nov. 2024, Peer-reviwed, True, Resistance exercise upregulates and downregulates the expression of a wide range of genes in skeletal muscle. However, detailed analysis of mRNA dynamics such as response rates and temporal patterns of the transcriptome after resistance exercise has not been performed. We aimed to clarify the dynamics of time-series transcriptomics after resistance exercise. We used electrical stimulation-induced muscle contraction as a resistance exercise model (5 sets × 10 times of 3 s of 100-Hz electrical stimulation) on the tibialis anterior muscle of rats and measured the transcriptome in the muscle before and at 0, 1, 3, 6, and 12 h after muscle contractions by RNA sequencing. We also examined the relationship between the parameters of mRNA dynamics and the increase in protein expression at 12 h after muscle contractions. We found that the function of the upregulated genes differed after muscle contractions depending on their response rate. Genes related to muscle differentiation and response to mechanical stimulus were enriched in the sustainedly upregulated genes. Furthermore, there was a positive correlation between the magnitude of upregulated mRNA expression and the corresponding protein expression level at 12 h after muscle contractions. Although it has been theoretically suggested, this study experimentally demonstrated that the magnitude of the mRNA response after electrical stimulation-induced resistance exercise contributes to skeletal muscle adaptation via increases in protein expression. These findings suggest that mRNA expression dynamics such as response rate, a sustained upregulated expression pattern, and the magnitude of the response contribute to mechanisms underlying adaptation to resistance exercise.
Scientific journal, English

In vivo intracellular Ca2+ profiles after eccentric rat muscle contractions: Addressing the mechanistic bases for repeated bout protection.
Ayaka Tabuchi; Yudai Kikuchi; Ryo Takagi; Yoshinori Tanaka; Daisuke Hoshino; David C Poole; Yutaka Kano
Last, Journal of applied physiology (Bethesda, Md. : 1985), 15 Nov. 2024, Peer-reviwed, True, Eccentric contractions (ECC) are accompanied by accumulation of intracellular calcium ions ([Ca2+]i) and induce skeletal muscle damage. Suppressed muscle damage in repeated bouts of ECC is well characterized, however, whether it is mediated by altered Ca2+ profiles remains unknown. PURPOSE: We tested the hypothesis that repeated ECC suppresses Ca2+ accumulation via adaptions in Ca2+ regulation. METHODS: Male Wistar rats were divided into two groups: ECC single bout (ECC-SB) and repeated bout (ECC-RB). Tibialis anterior (TA) muscles were subjected to ECC (40 times, 5 sets) once (ECC-SB), or twice 14 days apart (ECC-RB). Under anesthesia, the TA muscle was loaded with Ca2+ indicator Fura-2 AM and the 340/380 nm ratio was evaluated as [Ca2+]i. Ca2+ handling proteins were measured by western blots. RESULTS: ECC induced [Ca2+]i increase in both groups, but ECC-RB evinced a markedly suppressed [Ca2+]i (Time: P < 0.01, Group: P = 0.0357). 5 hours post-ECC, in contrast to the localized [Ca2+]i accumulation in ECC-SB, ECC-RB exhibited lower and more uniform [Ca2+]i (P < 0.01). In ECC-RB mitochondria Ca2+ uniporter complex components, MCU and MICU2, were significantly increased pre-second ECC bout (P < 0.01) and both SERCA1 and MICU1 were better preserved after contractions (P < 0.01). CONCLUSION: 14 days after novel ECC skeletal muscle mitochondrial Ca2+ regulating proteins were elevated. Following subsequent ECC [Ca2+]i accumulation and muscle damage were suppressed and SERCA1 and MICU1 preserved. These findings suggest that tolerance to a subsequent ECC bout is driven, at least in part, by enhanced mitochondrial and SR Ca2+ regulation.
Scientific journal, English

Muscle atrophy and mRNA-miRNA network analysis of vascular endothelial growth factor (VEGF) in a mouse model of denervation-induced disuse
Gaku Oguri; Ryo Ikegami; Haruka Ugawa; Manami Katoh; Syotaro Obi; Masashi Sakuma; Norihiko Takeda; Yutaka Kano; Shigeru Toyoda; Toshiaki Nakajima
Cureus, Springer science and business media LLC, 09 Sep. 2024, Peer-reviwed
Scientific journal

Intracellular Ca2+ after eccentric muscle contractions: Key role for ryanodine receptors.
Ayaka Tabuchi; David C Poole; Yutaka Kano
Corresponding, Exercise and sport sciences reviews, 05 Sep. 2024, Peer-reviwed, Invited, True, Eccentric contractions (ECC) induce excessive intracellular calcium ion (Ca2+) accumulation and muscle structural damage in localized regions of the muscle fibers. In this investigation, we present the novel hypothesis that the ryanodine receptor (RyR) plays a central role in evoking a Ca2+ dynamics profile that is markedly distinguishable from other muscle adaptive responses.
Scientific journal, English

Eccentric contraction increases hydrogen peroxide levels and alters gene expression through Nox2 in skeletal muscle of male mice
Ryotaro Kano; Tatsuya Kusano; Reo Takeda; Hideki Shirakawa; David C. Poole; Yutaka Kano; Daisuke Hoshino
Journal of applied physiology, American physiological society, 137, 3, 778-788, 01 Sep. 2024, Peer-reviwed, This in vivo model successfully characterized the effects of eccentric (ECC) and concentric (CONC) contractions on cytosolic and mitochondrial [H₂O₂] in mouse skeletal muscle. Compared with CONC, ECC induced higher and more sustained [H₂O₂]_cyto—an effect that was abolished by Nox2 inhibition. ECC-induced [H₂O₂]_cyto elevations were requisite for altered gene expression.
Scientific journal

Effect of diabetes on microvascular morphology and permeability of rat skeletal muscle: In vivo imaging using two-photon laser scanning microscopy
Kazuki Hotta; Rie Shimotsu; Bradley J. Behnke; Kazuto Masamoto; Kazuyoshi Yagishita; David C. Poole; Yutaka Kano
Last, Journal of applied physiology, American physiological society, 15 Aug. 2024, Peer-reviwed, This investigation evaluated the microvascular permeability and ultrastructure of skeletal muscle capillaries in skeletal muscle of diabetic (DIA) rats using two-photon laser scanning microscopy (TPLSM) and transmission electron microscopy (TEM). Microvascular permeability was assessed in the tibialis anterior muscle of control (CON) and DIA (streptozocin) male Wistar rats (n = 20, 10-14 wk) by in vivo imaging using TPLSM after fluorescent dye intravenous infusion. Fluorescent dye leakage was quantified to determine microvascular permeability. The ultrastructure was imaged by TEM ex vivo to calculate the size and number of intercellular clefts between capillary endothelial cells and also intracellular vesicles. Compared with control, the volumetrically determined interstitial fluorescent dye leakage, the endothelial cell thickness, and the number of intercellular clefts per capillary perimeter were significantly higher, and the cleft width was significantly narrower in TA of DIA (interstitial fluorescent dye leakage, 2.88 ± 1.40 vs. 10.95 ± 1.41 µm³ x min x 10⁶; endothelial thickness 0.28 ± 0.02 vs. 0.45 ± 0.03 µm; number of intercellular clefts per capillary perimeter 6.3 ± 0.80 vs. 13.6 ± 1.7 /100 µm; cleft width 11.92 ± 0.95 vs. 8.40 ± 1.03 nm, CON vs. DIA respectively, all p <0.05). The size of intracellular vesicles in the vascular endothelium showed an increased proportion of large vesicles in the DIA group compared to the CON group (p < 0.05). Diabetes mellitus enhances the microvascular permeability of skeletal muscle microvessels, due, in part, to a higher density and narrowing of the endothelial intercellular clefts, and larger intracellular vesicles.
Scientific journal

Cooling-promoted myogenic differentiation of murine bone marrow mesenchymal stem cells through TRPM8 activation in vitro.
Ryo Takagi; Junya Takegaki; Shion Osana; Yutaka Kano; Satoshi Konishi; Satoshi Fujita
Physiological reports, 11, 23, e15855, Dec. 2023, Peer-reviwed, True, TRPM8 agonist has been reported to promote osteogenic differentiation of mesenchymal stem cells (MSCs), therefore we evaluated whether cooling-induced activation of TRPM8 promotes myogenic differentiation of MSCs. We used 5-azacytidine as a myogenic differentiation inducer in murine bone marrow-derived MSCs. Addition of menthol, a TRPM8 agonist, to the differentiation induction medium significantly, increased the percentage of MyoD-positive cells, a specific marker of myogenic differentiation. We performed intracellular Ca2+ imaging experiments using fura-2 to confirm TRPM8 activation by cooling stimulation. The results confirmed that intracellular Ca2+ concentration ([Ca2+ ]i) increases due to TRPM8 activation, and TRPM8 antagonist inhibits increase in [Ca2+ ]i at medium temperatures below 19°C. We also examined the effect of cooling exposure time on myogenic differentiation of MSCs using an external cooling stimulus set at 17°C. The results showed that 60 min of cooling had an acceleratory effect on differentiation (2.18 ± 0.27 times). We observed that the TRPM8 antagonist counteracted the differentiation-promoting effect of the cooling. These results suggest that TRPM8 might modulate the multiple differentiation pathways of MSCs, and that cooling is an effective way of activating TRPM8, which regulates MSCs differentiation in vitro.
Scientific journal, English

In vivo heat production dynamics during a contraction-relaxation cycle in rat single skeletal muscle fibers.
Ayaka Tabuchi; Yoshinori Tanaka; Hiroshi Horikawa; Takuto Tazawa; David C Poole; Yutaka Kano
Last, Journal of thermal biology, 119, 103760-103760, 30 Nov. 2023, Peer-reviwed, True, Skeletal muscle generates heat via contraction-dependent (shivering) and independent (nonshivering) mechanisms. While this thermogenic capacity of skeletal muscle undoubtedly contributes to the body temperature homeostasis of animals and impacts various cellular functions, the intracellular temperature and its dynamics in skeletal muscle in vivo remain elusive. We aimed to determine the intracellular temperature and its changes within skeletal muscle in vivo during contraction and following relaxation. In addition, we tested the hypothesis that sarcoplasmic reticulum Ca2+ ATPase (SERCA) generates heat and increases the myocyte temperature during a transitory Ca2+-induced contraction-relaxation cycle. The intact spinotrapezius muscle of anesthetized adult male Wistar rats (n = 18) was exteriorized and loaded with the fluorescent probe Cellular Thermoprobe for Fluorescence Ratio (49.3 μM) by microinjection over 1 s. The fluorescence ratio (i.e., 580 nm/515 nm) was measured in vivo during 1) temperature increases induced by means of an external heater, and 2) Ca2+ injection (3.9 nL, 2.0 mM). The fluorescence ratio increased as a linear function of muscle surface temperature from 25 °C to 40 °C (r2 = 0.97, P < 0.01). Ca2+ injection (3.9 nL, 2.0 mM) significantly increased myocyte intracellular temperature: An effect that was suppressed by SERCA inhibition with cyclopiazonic acid (CPA, Ca2+: 38.3 ± 1.4 °C vs Ca2++CPA: 28.3 ± 2.8 °C, P < 0.01 at 1 min following injection). While muscle shortening occurred immediately after the Ca2+ injection, the increased muscle temperature was maintained during the relaxation phase. In this investigation, we demonstrated a novel model for measuring the intracellular temperature of skeletal muscle in vivo and further that heat generation occurs concomitant principally with SERCA functioning and muscle relaxation.
Scientific journal, English

Cmah deficiency blunts cellular senescence in adipose tissues and improves whole-body glucose metabolism in aged mice.
Reo Takeda; Ayaka Tabuchi; Yudai Nonaka; Ryotaro Kano; Mizuki Sudo; Yutaka Kano; Daisuke Hoshino
Geriatrics & gerontology international, 15 Nov. 2023, Peer-reviwed, False, AIM: Cytidine monophosphate-N-acetylneuraminic acid (Neu5Ac) hydroxylase (Cmah) is an enzyme, which converts Neu5Ac to the sialic acid Neu5Gc. Neu5Gc is thought to increase inflammatory cytokines, which are, in part, produced in senescent cells of adipose tissues. Cellular senescence in adipose tissues induces whole-body aging and impaired glucose metabolism. Therefore, we hypothesized that Cmah deficiency would prevent cellular senescence in adipose tissues and impaired glucose metabolism. METHODS: Wild-type (WT) and Cmah knockout (KO) mice aged 24-25 months were used. Whole-body metabolism was assessed using a metabolic gas analysis system. We measured blood glucose and insulin concentrations after oral glucose administration. The size of the lipid droplets in the liver was quantified. Markers of cellular senescence and senescence-associated secretory phenotypes were measured in adipose tissues. RESULTS: Cmah KO had significantly increased VO2 and energy expenditure (P < 0.01). Unlike glucose, the insulin concentration after oral glucose administration was significantly lower in the Cmah KO group than in the WT group (P < 0.001). Lipid droplets in the liver were significantly lower in the Cmah KO group than in the WT group (P < 0.05). The markers of cellular senescence and senescence-associated secretory phenotypes in the adipose tissues were significantly lower in the Cmah KO group than in the WT group (P < 0.05). CONCLUSIONS: Cmah deficiency blunted cellular senescence in adipose tissues and improved whole-body glucose metabolism. These characteristics in aged Cmah KO mice might be associated with higher energy expenditure. Geriatr Gerontol Int 2023; ••: ••-••.
Scientific journal, English

Cooling of male rat skeletal muscle during endurance-like contraction attenuates contraction-induced PGC-1α mRNA expression.
Daisuke Hoshino; Ryota Wada; Yutaro Mori; Reo Takeda; Yudai Nonaka; Ryotaro Kano; Ryo Takagi; Yutaka Kano
Last, Physiological reports, 11, 21, e15867, Nov. 2023, Peer-reviwed, True, This study aimed to determine effects of cooling on contraction-induced peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and vascular endothelial growth factor (VEGF) gene expression, phosphorylations of its related protein kinases, and metabolic responses. Male rats were separated into two groups; room temperature (RT) or ice-treated (COLD) on the right tibialis anterior (TA). The TA was contracted isometrically using nerve electrical stimulation (1-s stimulation × 30 contractions, with 1-s intervals, for 10 sets with 1-min intervals). The TA was treated before the contraction and during 1-min intervals with an ice pack for the COLD group and a water pack at RT for the RT group. The muscle temperature of the COLD group decreased to 19.42 ± 0.44°C (p < 0.0001, -36.4%) compared with the RT group after the experimental protocol. An increase in mRNA expression level of PGC-1α, not VEGF, after muscle contractions was significantly lower in the COLD group than in the RT group (p < 0.0001, -63.0%). An increase in phosphorylated AMP-activated kinase (AMPK) (p = 0.0037, -28.8%) and a decrease in glycogen concentration (p = 0.0231, +106.3%) after muscle contraction were also significantly inhibited by cooling. Collectively, muscle cooling attenuated the post-contraction increases in PGC-1α mRNA expression coinciding with decreases in AMPK phosphorylation and glycogen degradation.
Scientific journal, English

In vivo cytosolic H2O2 changes and Ca2+ homeostasis in mouse skeletal muscle.
Ryotaro Kano; Ayaka Tabuchi; Yoshinori Tanaka; Hideki Shirakawa; Daisuke Hoshino; David C Poole; Yutaka Kano
Corresponding, American journal of physiology. Regulatory, integrative and comparative physiology, 30 Oct. 2023, Peer-reviwed, True, Hydrogen peroxide (H2O2) and calcium ions (Ca2+) are functional regulators of skeletal muscle contraction and metabolism. Although H2O2 is one of the activators of the type-1 ryanodine receptor (RyR1) in the Ca2+ release channel, the interdependence between H2O2 and Ca2+ dynamics remains unclear. This study tested the following hypotheses using an in vivo model of mouse tibialis anterior (TA) skeletal muscle. 1. Under resting conditions, elevated cytosolic H2O2 concentration ([H2O2]cyto) leads to a concentration-dependent increase in cytosolic Ca2+concentration ([Ca2+]cyto) through its effect on RyR1. 2. In hypoxia (cardiac arrest) and muscle contractions (electrical stimulation), increased [H2O2]cyto induce Ca2+ accumulation. Cytosolic H2O2 (HyPer7) and Ca2+ (Fura-2) dynamics were resolved by TA bioimaging in C57BL/6J male mice under four conditions: Elevated exogenous H2O2, Cardiac arrest, Twitch and Tetanic contractions. Exogenous H2O2 (0.1-100mM) induced a concentration-dependent increase in [H2O2]cyto (+55%,0.1mM; +280%,100mM) and an increase in [Ca2+]cyto (+3%,1.0mM; +8%,10mM). This increase in [Ca2+]cyto was inhibited by pharmacological inhibition of RyR1 by dantrolene. Cardiac arrest-induced hypoxia increased [H2O2]cyto (+33%) and [Ca2+]cyto (+20%) 50min post-cardiac arrest. Compared to exogenous 1.0mM H2O2 condition, [H2O2]cyto after tetanic contractions rose less than one-tenth as much, while [Ca2+]cyto was 4.7-fold higher. In conclusion, substantial increases in [H2O2]cyto levels evoke only modest Ca2+ accumulation via their effect on the sarcoplasmic reticulum RyR1. On the other hand, contrary to hypoxia secondary to cardiac arrest, increases in [H2O2]cyto from contractions are small, indicating that H2O2 generation is unlikely to be a primary factor driving the significant Ca2+ accumulation after, especially tetanic, muscle contractions.
Scientific journal, English

The effects of environmental enrichment on voluntary physical activity and muscle mass gain in growing rats
Mizuki Sudo; Yutaka Kano; Soichi Ando
Frontiers in Physiology, Frontiers Media SA, 14, 28 Sep. 2023, Peer-reviwed, Introduction: Environmental enrichment (EE) for rodents involves housing conditions that facilitate enhanced sensory, cognitive, and motor stimulation relative to standard housing conditions. A recent study suggested that EE induces muscle hypertrophy. However, it remains unclear whether muscle hypertrophy in EE is associated with voluntary physical activity, and the characteristics of muscle adaptation to EE remain unclarified. Therefore, this study investigated whether muscle adaptation to EE is associated with voluntary physical activity, and assessed the changes in the muscle fiber-type distribution and fiber-type-specific cross-sectional area in response to EE.

Methods: Wistar rats (6 weeks of age) were randomly assigned to either the standard environment group (n = 10) or the EE group (n = 10). The voluntary physical activity of rats housed in EE conditions was measured using a recently developed three-axis accelerometer. After exposure to the standard or enriched environment for 30 days, the tibialis anterior, extensor digitorum longus, soleus, plantaris, and gastrocnemius muscles were removed and weighed. Immunohistochemistry analysis was performed on the surface (anterior) and deep (posterior) areas of the tibialis anterior and soleus muscles.

Results and discussion: The EE group showed increased voluntary physical activity during the dark period compared with the standard environment group (p = 0.005). EE induced muscle mass gain in the soleus muscle (p = 0.002) and increased the slow-twitch muscle fiber cross-sectional area of the soleus muscle (p = 0.025). EE also increased the distribution of high-oxidative type IIa fibers of the surface area (p = 0.001) and type I fibers of the deep area (p = 0.037) of the tibialis anterior muscle. These findings suggest that EE is an effective approach to induce slow-twitch muscle fiber hypertrophy through increased daily voluntary physical activity.
Scientific journal

The aminopeptidase LAP3 suppression accelerates myogenic differentiation via the AKT-TFE3 pathway in C2C12 myoblasts.
Shion Osana; Yasuo Kitajima; Suzuki Naoki; Kazutaka Murayama; Hiroaki Takada; Ayaka Tabuchi; Yutaka Kano; Ryoichi Nagatomi
Journal of cellular physiology, 12 Jul. 2023, Peer-reviwed, True, Skeletal muscle maintenance depends largely on muscle stem cells (satellite cells) that supply myoblasts required for muscle regeneration and growth. The ubiquitin-proteasome system is the major intracellular protein degradation pathway. We previously reported that proteasome dysfunction in skeletal muscle significantly impairs muscle growth and development. Furthermore, the inhibition of aminopeptidase, a proteolytic enzyme that removes amino acids from the termini of peptides derived from proteasomal proteolysis, impairs the proliferation and differentiation ability of C2C12 myoblasts. However, no evidence has been reported on the role of aminopeptidases with different substrate specificities on myogenesis. In this study, therefore, we investigated whether the knockdown of aminopeptidases in differentiating C2C12 myoblasts affects myogenesis. The knockdown of the X-prolyl aminopeptidase 1, aspartyl aminopeptidase, leucyl-cystinyl aminopeptidase, methionyl aminopeptidase 1, methionyl aminopeptidase 2, puromycine-sensitive aminopeptidase, and arginyl aminopeptidase like 1 gene in C2C12 myoblasts resulted in defective myogenic differentiation. Surprisingly, the knockdown of leucine aminopeptidase 3 (LAP3) in C2C12 myoblasts promoted myogenic differentiation. We also found that suppression of LAP3 expression in C2C12 myoblasts resulted in the inhibition of proteasomal proteolysis, decreased intracellular branched-chain amino acid levels, and enhanced mTORC2-mediated AKT phosphorylation (S473). Furthermore, phosphorylated AKT induced the translocation of TFE3 from the nucleus to the cytoplasm, promoting myogenic differentiation through increased expression of myogenin. Overall, our study highlights the association of aminopeptidases with myogenic differentiation.
Scientific journal, English

Chronic repetitive cooling and caffeine-induced intracellular Ca²⁺ elevation differentially impact adaptations in slow- and fast-twitch rat skeletal muscles
Ryo Takagi; Ayaka Tabuchi; Kosei Hayakawa; Shion Osana; Hiroya Yabuta; Daisuke Hoshino; David C. Poole; Yutaka Kano
Last, American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, American Physiological Society, 19 Jun. 2023, Peer-reviwed, Intracellular Ca²⁺ concentration ([Ca²⁺]i) is considered important in the regulation of skeletal muscle mass. This study tested the hypothesis that chronic repeated cooling and/or caffeine ingestion would acutely increase [Ca²⁺]i and hypertrophy muscles potentially in a fiber type-dependent manner. Control rats and those fed caffeine, were subjected to repeated bidiurnal treatments of percutaneous icing, under anaesthesia, to reduce the muscle temperature below ~5°C. The predominantly fast twitch tibialis anterior (TA) and slow twitch soleus (SOL) muscles were evaluated after 28 days intervention. The [Ca²⁺]i elevating response to icing was enhanced by caffeine loading only in the SOL muscle, with the response present across a significantly higher temperature range than in the TA muscle under caffeine loading conditions. In both the TA and SOL muscles, myofiber cross-sectional area (CSA) was decreased by chronic caffeine treatment (mean reductions of 10.5% and 20.4%, respectively). However, in the TA , but not the SOL, CSA was restored by icing (+15.4 ± 4.3% vs. non-iced, P<0.01). In the SOL but not TA, icing+caffeine increased myofiber number (20.5 ± 6.7%, P<0.05) and satellite cell density (2.5 ± 0.3-fold) in cross sections. These contrasting muscle responses to cooling and caffeine may reflect fiber-type specific [Ca²⁺]i responses and/or differential responses to elevated [Ca²⁺]i.
Scientific journal

Little involvement of recycled-amino acids from proteasomal proteolysis in de novo protein synthesis.
Shion Osana; Yasuo Kitajima; Suzuki Naoki; Hiroaki Takada; Kazutaka Murayama; Yutaka Kano; Ryoichi Nagatomi
Biochem Biophys Res Commun, 634, 40-47, 02 Oct. 2022, Peer-reviwed
Scientific journal, English

Effect of endurance training and PGC-1α overexpression on calculated lactate production volume during exercise based on blood lactate concentration.
Reo Takeda; Yudai Nonaka; Katsuyuki Kakinoki; Shinji Miura; Yutaka Kano; Daisuke Hoshino
Scientific reports, 12, 1, 1635, 31 Jan. 2022, Peer-reviwed, True, Lactate production is an important clue for understanding metabolic and signal responses to exercise but its measurement is difficult. Therefore, this study aimed (1) to develop a method of calculating lactate production volume during exercise based on blood lactate concentration and compare the effects between endurance exercise training (EX) and PGC-1α overexpression (OE), (2) to elucidate which proteins and enzymes contribute to changes in lactate production due to EX and muscle PGC-1α OE, and (3) to elucidate the relationship between lactate production volume and signaling phosphorylations involved in mitochondrial biogenesis. EX and PGC-1α OE decreased muscle lactate production volume at the absolute same-intensity exercise, but only PGC-1α OE increased lactate production volume at the relative same-intensity exercise. Multiple linear regression revealed that phosphofructokinase, monocarboxylate transporter (MCT)1, MCT4, and citrate synthase equally contribute to the lactate production volume at high-intensity exercise within physiological adaptations, such as EX, not PGC-1α OE. We found that an exercise intensity-dependent increase in the lactate production volume was associated with a decrease in glycogen concentration and an increase in P-AMPK/T-AMPK. This suggested that the calculated lactate production volume was appropriate and reflected metabolic and signal responses but further modifications are needed for the translation to humans.
Scientific journal, English

Ryanodine receptors mediate high intracellular Ca2+ and some myocyte damage following eccentric contractions in rat fast-twitch skeletal muscle.
Ayaka Tabuchi; Yoshinori Tanaka; Ryo Takagi; Hideki Shirakawa; Tsubasa Shibaguchi; Takao Sugiura; David C Poole; Yutaka Kano
Corresponding, American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 322, 1, 14-27, 01 Jan. 2022, Peer-reviwed, True, Eccentric contractions (ECC) facilitate cytosolic calcium ion (Ca2+) release from the sarcoplasmic reticulum (SR) and Ca2+ influx from the extracellular space. Ca2+ is a vital signaling messenger that regulates multiple cellular processes via its spatial and temporal concentration ([Ca2+]i) dynamics. We hypothesized that 1) a specific pattern of spatial/temporal intramyocyte Ca2+ dynamics portends muscle damage following ECC and 2) these dynamics would be regulated by the ryanodine receptor (RyR). [Ca2+]i in the tibialis anterior muscles of anesthetized adult Wistar rats was measured by ratiometric (i.e., ratio, R, 340/380 nm excitation) in vivo bioimaging with Fura-2 pre-ECC and at 5 and 24 h post-ECC (5 × 40 contractions). Separate groups of rats received RyR inhibitor dantrolene (DAN; 10 mg/kg ip) immediately post-ECC (+DAN). Muscle damage was evaluated by histological analysis on hematoxylin-eosin stained muscle sections. Compared with control (CONT, no ECC), [Ca2+]i distribution was heterogeneous with increased percent total area of high [Ca2+]i sites (operationally defined as R ≥ 1.39, i.e., ≥1 SD of mean control) 5 h post-ECC (CONT, 14.0 ± 8.0; ECC5h: 52.0 ± 7.4%, P < 0.01). DAN substantially reduced the high [Ca2+]i area 5 h post-ECC (ECC5h + DAN: 6.4 ± 3.1%, P < 0.01) and myocyte damage (ECC24h, 63.2 ± 1.0%; ECC24h + DAN: 29.1 ± 2.2%, P < 0.01). Temporal and spatially amplified [Ca2+]i fluctuations occurred regardless of DAN (ECC vs. ECC + DAN, P > 0.05). These results suggest that the RyR-mediated local high [Ca2+]i itself is related to the magnitude of muscle damage, whereas the [Ca2+]i fluctuation is an RyR-independent phenomenon.
Scientific journal, English

Predominant cause of faster force recovery in females than males after intense eccentric contractions in mouse fast-twitch muscle.
Daiki Watanabe; Ryo Ikegami; Yutaka Kano
Last, The Journal of Physiology, 599, 18, 4337-4356, 08 Aug. 2021, Peer-reviwed, True, KEY POINTS: We investigated the mechanisms underlying faster force recovery from eccentric contractions (ECCs) in female than in male mice, focusing on mitochondrial responses. At 3 days after repeated ECCs (REC3), female mice showed faster recovery from ECC-induced force depression than male mice. At REC3, the mitochondria in females displayed superior responses to those in males: (i) mitochondrial Ca2+ uniporter content of muscles at REC3 was higher than that of rested muscles in females, and (ii) mitochondrial volume density in females was higher than that in males at REC3. Ovariectomized (OVX) female mice showed lower mitochondrial responses at REC3, similar to those observed in male mice, but oestrogen replacement nullified such lower responses in OVX. We concluded that: (i) superior mitochondrial responses after ECCs, at least in part, cause faster force recovery from ECCs in females than in males, and (ii) oestrogen contributes to such superior responses in the mitochondria in females. ABSTRACT: The purpose of this study was to investigate the mechanisms underlying sex differences in force recovery after eccentric contractions (ECCs). The left limbs of female and male mice were exposed to repeated ECCs (five sets of 50 contractions) elicited in vivo in the plantar flexor muscles. Isometric torques were measured before, immediately and at 3 days after ECCs (REC3), and gastrocnemius muscles obtained at REC3 were used for biochemical and morphological analyses. At REC3, a greater torque depression at 40 Hz was observed in males than females. Additionally, the following differences were observed at REC3: (i) in males but not females, triad structure was distorted, (ii) mitochondrial Ca2+ uniporter (MCU) content was increased in females but not in males, and (iii) mitochondrial volume density at REC3 was lower in males than in females. To examine the contribution of oestrogen to torque recovery, female mice were assigned to sham-operated (Sham), ovariectomized (OVX) and OVX treated with 17β-oestradiol (OVX + E2) groups. At REC3, (i) greater torque depression at 40 Hz was observed in the OVX group than in the Sham and OVX + E2 groups, (ii) MCU content was increased in the Sham and OVX + E2 groups but not the OVX group, and (iii) mitochondrial volume density at REC3 was lower in the OVX group than the Sham and OVX + E2 groups. These results suggest that faster force recovery in females than in males is, at least partly, ascribable to superior mitochondrial responses, and oestrogen supplementation, in part, enhances such responses.
Scientific journal, English

In vivo cooling-induced intracellular Ca2+ elevation and tension in rat skeletal muscle.
Ryo Takagi; Ayaka Tabuchi; David C Poole; Yutaka Kano
Corresponding, Physiological Reports, 9, 13, e14921-e14921, 09 Jul. 2021, Peer-reviwed, True, It is an open question as to whether cooling-induced muscle contraction occurs in the in vivo environment. In this investigation, we tested the hypotheses that a rise in intracellular Ca²⁺ concentration ([Ca²⁺]i) and concomitant muscle contraction could be evoked in vivo by reducing muscle temperature and that this phenomenon would be facilitated or inhibited by specific pharmacological interventions designed to impact Ca²⁺-induced Ca²⁺-release (CICR). Progressive temperature reductions were imposed on the spinotrapezius muscle of Wistar rats under isoflurane anesthesia by means of cold fluid immersion. The magnitude, location, and temporal profile of [Ca²⁺]i were estimated using fura-2 loading. Caffeine (1.25-5.0 mM) and procaine (1.6-25.6 mM) loading were applied in separatum to evaluate response plasticity by promoting or inhibiting CICR, respectively. Lowering the temperature of the muscle surface to ~5°C produced active tension and discrete sites with elevated [Ca²⁺]i. This [Ca²⁺]i elevation differed in magnitude from fiber to fiber and also from site to site within a fiber. Caffeine at 1.25 and 5.0 mM reduced the magnitude of cooling necessary to elevate [Ca²⁺]i (i.e., from ~5°C to ~8 and ~16°C, respectively, both p < 0.05) and tension. Conversely, 25.6 mM procaine lowered the temperature at which [Ca²⁺]i elevation and tension were detected to ~2°C (p < 0.05). Herein we demonstrate the spatial and temporal relationship between cooling-induced [Ca²⁺]i elevation and muscle contractile force in vivo and the plasticity of these responses with CICR promotion and inhibition.
Scientific journal, English

Vascular permeability of skeletal muscle microvessels in rat arterial ligation model: in vivo analysis using two-photon laser scanning microscopy.
Shimotsu, Rie; Hotta, Kzuki; Ikegami, Ryo; Asamura, Tomoyo; Tabuchi, Ayaka; Masamoto, Kazuto; Yagishita; Kazuyoshi; Poole; David C; Kano, Yutaka
Corresponding, American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, 320, 6, R972-R983, 05 May 2021, Peer-reviwed, True, Peripheral artery disease (PAD) in the lower limb compromises oxygen supply due to arterial occlusion. Ischemic skeletal muscle is accompanied by capillary structural deformation. Therefore, using novel microscopy techniques, we tested the hypothesis that endothelial cell swelling temporally and quantitatively corresponds to enhanced microvascular permeability. Hindlimb ischemia was created in male Wistar rat's by iliac artery ligation (AL). The tibialis anterior (TA) muscle microcirculation was imaged using intravenously infused rhodamine B isothiocyanate dextran fluorescent dye via two-photon laser scanning microscopy (TPLSM) and dye extravasation at 3 and 7 days post-AL quantified to assess microvascular permeability. The TA microvascular endothelial ultrastructure was analyzed by transmission electron microscopy (TEM). Compared with control (0.40 ± 0.15 μm3 × 106), using TPLSM, the volumetrically determined interstitial leakage of fluorescent dye measured at 3 (3.0 ± 0.40 μm3 × 106) and 7 (2.5 ± 0.8 μm3 × 106) days was increased (both P < 0.05). Capillary wall thickness was also elevated at 3 (0.21 ± 0.06 μm) and 7 (0.21 ± 0.08 μm) days versus control (0.11 ± 0.03 μm, both P < 0.05). Capillary endothelial cell swelling was temporally and quantitatively associated with elevated vascular permeability in the AL model of PAD but these changes occurred in the absence of elevations in protein levels of vascular endothelial growth factor (VEGF) its receptor (VEGFR2 which decreased by AL-7 day) or matrix metalloproteinase. The temporal coherence of endothelial cell swelling and increased vascular permeability supports a common upstream mediator. TPLSM, in combination with TEM, provides a sensitive and spatially discrete technique to assess the mechanistic bases for, and efficacy of, therapeutic countermeasures to the pernicious sequelae of compromised peripheral arterial function.
Scientific journal, English

Short-Term Calorie Restriction Maintains Plasma Insulin Concentrations along with a Reduction in Hepatic Insulin-Degrading Enzyme Levels in db/db Mice.
Yudai Nonaka; Reo Takeda; Yutaka Kano; Daisuke Hoshino
Nutrients, MDPI AG, 13, 4, 1190-1190, 03 Apr. 2021, Peer-reviwed, Maintaining blood insulin levels is important for patients with diabetes because insulin secretion capacity declines with the development of the disease. Calorie restriction (CR) is effective for the improvement of glucose tolerance, but it is not clear whether CR can maintain insulin levels in the late stage of diabetes. We examined the effect of CR on whole-body glucose tolerance and fasting blood insulin concentrations in the late stage of diabetes. Male db/db mice were subjected to either a standard laboratory diet ad libitum for 3 weeks (dbdb group) or 40% CR (dbdb+CR group). CR significantly decreased body mass and epididymal fat weight. Glucose tolerance and fasting glucose levels were significantly improved with 3-week CR. Fasting insulin concentrations were decreased in the dbdb group but were maintained in the dbdb+CR group. CR significantly reduced insulin-degrading enzyme (IDE) levels in the liver, and hepatic IDE levels were significantly positively and negatively correlated with plasma glucose concentrations (area under the curve) after glucose administration and after fasting insulin concentrations, respectively. Therefore, 3-week CR maintained blood insulin levels and improved glucose tolerance with decreased hepatic IDE levels in an animal model of late-stage diabetes.
Scientific journal, English

Type I diabetes suppresses intracellular calcium ion increase normally evoked by heat stress in rat skeletal muscle.
Ryo Ikegami; Hiroaki Eshima; Toshiaki Nakajima; Shigeru Toyoda; David C Poole; Yutaka Kano
Corresponding, American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, American Physiological Society, 320, 4, R384-R392, 01 Apr. 2021, Peer-reviwed, Heat stress, via its effects on muscle intracellular Ca²⁺ concentrations ([Ca²⁺]i), has been invoked as a putative therapeutic countermeasure to Type 1 diabetes-induced muscle atrophy. Using in vivo muscle preparation we tested the hypothesis that impaired muscle Ca²⁺ homeostasis in type I diabetic rats is due to attenuated heat stress tolerance mediated via TRPV1. Male Wistar rats were assigned to 1 of 4 groups: 1.control 30^oC (CONT 30^oC), 2.CONT 40^oC, 3.diabetes 30^oC (DIA 30^oC), 4.DIA 40^oC. 40^oC was selected because it just exceeds the TRPV1 activation threshold. Spinotrapezius muscles were exteriorized in vivo and loaded with the fluorescent Ca²⁺ probe Fura-2AM. [Ca²⁺]i was estimated over 20min using fluorescence microscopy in quiescent muscle held at the required temperature using calibrated heat source applied to the ventral muscle surface. Western blotting was performed to determine the protein expression levels of TRPV1 in spinotrapezius muscle. After 20min of heat stress, the CONT 40^oC condition induced a 12.3% [Ca²⁺]i elevation that was absent from the DIA 40^oC or other conditions. Thus, no significant differences were found among DIA 40^oC, DIA 30^oC and CONT 30^oC. TRPV1 protein expression was decreased by 42.0% in DIA compared with CONT (P<0.05) and, unlike CONT, heat stress did not increase TRPV1 phosphorylation. In conclusion, diabetes suppresses TRPV1 protein expression and function and inhibits the elevated myocyte [Ca²⁺]i evoked normally by heat stress. These results suggest that capsaicin or other therapeutic strategies to increase Ca²⁺ accumulation via TRPV1 might be more effective than hyperthermic therapy for Type I diabetic patients.
Scientific journal, English

In vivo Ca2+ dynamics during cooling after eccentric contractions in rat skeletal muscle
Ryo Takagi; Ayaka Tabuchi; Tomoyo Asamura; Seiya Hirayama; Ryo Ikegami; Yoshinori Tanaka; Daisuke Hoshino; David C Poole; Yutaka Kano
Corresponding, American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, 320, 2, 129-137, 18 Nov. 2020, Peer-reviwed, True, The effect of cooling on in vivo intracellular calcium ion concentration [Ca2+]i after eccentric contractions (ECs) remains to be determined. We tested the hypothesis that cryotherapy following ECs promotes an increased [Ca2+]i and induces greater muscle damage in two muscles with substantial IIb and IIx fiber populations. The thin spinotrapezius (SPINO) muscles of Wistar rats were used for in vivo [Ca2+]i imaging, and tibialis anterior (TA) muscles provided greater fidelity and repeatability of contractile function measurements. SPINO [Ca2+]i was estimated using fura 2-AM and the magnitude, location, and temporal profile of [Ca2+]i determined as the temperature near the muscle surface post-ECs was decreased from 30°C (control) to 20°C or 10°C. Subsequently, in the TA, the effect of post-ECs cooling to 10°C on muscle contractile performance was determined at 1 and 2 days after ECs. TA muscle samples were examined by hematoxylin and eosin staining to assess damage. In SPINO, reducing the muscle temperature from 30°C to 10°C post-ECs resulted in a 3.7-fold increase in the spread of high [Ca2+]i sites generated by ECs (P < 0.05). These high [Ca2+]i sites demonstrated partial reversibility when rewarmed to 30°C. Dantrolene, a ryanodine receptor Ca2+ release inhibitor, reduced the presence of high [Ca2+] sites at 10°C. In the TA, cooling exacerbated ECs-induced muscle strength deficits via enhanced muscle fiber damage (P < 0.05). By demonstrating that cooling post-ECs potentiates [Ca2+]i derangements, this in vivo approach supports a putative mechanistic basis for how postexercise cryotherapy might augment muscle fiber damage and decrease subsequent exercise performance.
Scientific journal, English

August Krogh: Muscle capillary function and oxygen delivery.
David C Poole; Yutaka Kano; Shunsaku Koga; Timothy I Musch
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 253, 1-8, 18 Oct. 2020, Peer-reviwed
Scientific journal, English

Effects of acute 3-h swimming exercise on insulin secretion capacity of pancreatic islets.
Yudai Nonaka; Reo Takeda; Yutaka Kano; Daisuke Hoshino
The Journal of Physical Fitness and Sports Medicine, The Japanese Society of Physical Fitness and Sports Medicine, 9, 4, 173-179, 01 Sep. 2020, Peer-reviwed
Scientific journal, English

Effects of electrical stimulation‐induced resistance exercise training on white and brown adipose tissues and plasma meteorin‐like concentration in rats.
Kouhei Amano; Yudai Nonaka Reo; Takeda Yutaka; Yutaka Kano; Daisuke Hoshino
Physiological Reports, Wiley, 7, 19, e14266.-e14266., 18 Aug. 2020, Peer-reviwed
Scientific journal, English

Systemic NOS inhibition reduces contracting muscle oxygenation more in intact female than male rats.
Tabuchi A; Craig JC; Hirai DM; Colburn TD; Kano Y; Poole DC; Musch TI
Nitric Oxide., 100-101, 38-44, 01 Aug. 2020, Peer-reviwed, True, Females respond to baroreceptor stimulation with enhanced modulation of heart rate (HR) to regulate blood pressure and also express greater reliance on nitric oxide (NO) for vascular control compared to males. Sex differences in muscle oxygenation consequent to central hemodynamic challenge induced by systemic NO synthase (NOS) inhibition are unknown. We tested the hypotheses that systemic NOS inhibition would induce lower contracting skeletal muscle oxygenation in females compared to males. The spinotrapezius of Sprague-Dawley rats (females (♀) = 9, males (♂) = 9) was surgically exposed and contracted by electrical stimulation (180s, 1 Hz, ~6 V) under pentobarbital sodium anesthesia. Oxyphor G4 was injected into the muscle and phosphorescence quenching was used to measure the interstitial PO2 (PO2is, determined by O2 delivery-to-utilization matching) under control (Krebs-Henseleit solution) and after intra-arterial infusion of nitro-l-arginine methyl ester (l-NAME; NOS blockade; 10 mg kg-1). At rest, females showed a greater PO2is increase (ΔPO2is/ΔMAP) and HR (ΔHR/ΔMAP) reduction than males in response to the elevated MAP induced by systemic NOS inhibition (both p < 0.05). Following l-NAME, during the contracting steady-state, females exhibited lower PO2is than males (♂: 17.1 ± 1.4 vs ♀: 10.8 ± 1.4 mmHg, p < 0.05). The rate pressure product was lower in females than males (♂: 482 ± 14 vs ♀: 392 ± 29, p < 0.05) and correlated with the steady-state PO2is (r = 0.66, p < 0.05). These results support that females express greater reductions in HR than males in response to l-NAME-induced elevation of MAP via the baroreceptor reflex and provide new insights on how central hemodynamics affect skeletal muscle oxygenation in a sex-specific manner.
Scientific journal, English

Sex differences in mitochondrial Ca2+ handling in mouse fast-twitch skeletal muscle in vivo.
Daiki Watanabe; Koji Hatakeyama; Ryo Ikegami; Hiroaki Eshima; Kazuyoshi Yagishita; David C Poole; Yutaka Kano
Corresponding, Journal of Applied Physiology, 128, 2, 241-251, 01 Feb. 2020, Peer-reviwed, True, We investigated sex differences in mitochondrial Ca2+ handling properties in mouse fast-twitch skeletal muscle. Changes in cytoplasmic Ca2+ concentration ([Ca2+]cyto) were measured in vivo using tibialis anterior muscles from male and female mice. The muscles were exposed to increasing concentrations of cyclopiazonic acid [CPA; sarcoplasmic reticulum (SR) Ca2+-ATPase inhibitor] (from 10 to 30 to 50 μM at 10 min intervals). Thirty minutes after treatment, [Ca2+]cyto was increased by 31.6 ± 2.0% and 13.5 ± 4.5% of initial [Ca2+]cyto in male and female muscles, respectively, and there was a significant difference between sexes. However, muscle preincubation for 5 min with 10 μM carbonyl cyanide-4-(trifluoromethoxy) phenylhydrazone (an inhibitor of mitochondria Ca2+ uptake) eradicated this difference between sexes with respect to the CPA-induced [Ca2+]cyto increase. Both intermyofibrillar mitochondrial number and volume, assessed in longitudinal fiber sections, were higher in females compared with males (mitochondria number: 13.1 ± 1.0 in males vs. 19.9 ± 2.3 in females; mitochondrial volume: 0.034 ± 0.004 μm3/μm3 fiber volume in males vs. 0.066 ± 0.008 μm3/μm3 fiber volume in females, both P < 0.05). There were no sex differences in the content of SR Ca2+-ATPase, mitochondrial Ca2+ uniporter, mitofusin (Mfn) 1, or Mfn2. These results suggest that 1) mitochondrial Ca2+ uptake ability is greater in female than male myocytes, and 2) this superior Ca2+ uptake ability of female myocytes is due, partly, to the higher intermyofibrillar mitochondrial content but not to the expression of mitochondrial proteins related to mitochondrial Ca2+ uptake.NEW & NOTEWORTHY This investigation presents evidence that female versus male fast-twitch muscle exhibits a greater mitochondrial calcium ion uptake capability that is partly conferred by the higher intermyofibrillar mitochondrial volume density.
Scientific journal, English

Three-dimensional Microscopic Imaging Through Scattering Media Based on In-Line Phase-Shift Digital Holography
Shutaro Kodama; Manami Ohta; Kanami Ikeda; Yutaka Kano; Yoko Miyamoto; Wolfgang Osten; Mitsuo Takeda; Eriko Watanabe
Applied optics, OSA Publishing, 58, 34, G345-G345, 01 Dec. 2019, Peer-reviwed, Microscopic three-dimensional imaging and phase quantification for objects hidden behind a scattering medium by using in-line phase-shift digital holography are proposed. A spatial resolution of 1.81 µm and highly accurate quantitative phase imaging are demonstrated for objects behind a scatter plate. Three-dimensional imaging was confirmed using objects with a depth difference of 1.32 mm. Further, imaging was performed using rat skin as a demonstration for imaging through a complex multilayer scattering medium, where a spatial resolution close to the theoretically predicted value was achieved by experiment.
Scientific journal, English

Effects of clenbuterol administration on mitochondrial morphology and its regulatory proteins in rat skeletal muscle.
Yu Kitaoka; Daiki Watanabe; Yudai Nonaka; Kazuyoshi Yagishita; Yutaka Kano; Daisuke Hoshino
Physiol Rep, 7, 19, e14266-e14266, Oct. 2019, Clenbuterol induces a slow-to-fast fiber type transition in skeletal muscle. This muscle fiber transition decreased mitochondrial oxidative capacity and respiratory function. We hypothesized that the clenbuterol-mediated reduction in oxidative capacity is associated with the alteration in mitochondrial morphology. To verify this hypothesis, we examined whether clenbuterol alters mitochondrial morphology and mitochondrial regulatory proteins in rat skeletal muscle. Clenbuterol was administered to rats via drinking water (30 mg/L) for 3 weeks. Myosin heavy chain (MHC) isoform composition, mitochondrial morphology, and fusion and fission regulatory protein levels in deep region and superficial region in tibialis anterior (TA) muscles were assessed. Clenbuterol induced the fiber type transition from slow to fast in both the regions of TA. The levels of optic atrophy protein 1, mitofusin 2, and mitochondrial fission 1, but not of dynamin-related protein 1, significantly decreased in deep and superficial muscles after clenbuterol administration (P < 0.01). Also, observation using the transmission electron microscopy showed a decrease in mitochondrial volume (P < 0.05) and an increa
English

Skeletal muscle interstitial PO2 kinetics during recovery from contractions.
Daniel Hirai; Jesse Craig; Trenton Colburn; Hiroaki Eshima; Yutaka Kano; Timothy Musch; David Poole
Journal of Applied Physiology, The American Physiological Society (APS), 127, 4, 930-939, 01 Oct. 2019, Peer-reviwed, True, The oxygen partial pressure in the interstitial space (Po2 is) drives O2 into the myocyte via diffusion, thus supporting oxidative phosphorylation. Although crucial for metabolic recovery and the capacity to perform repetitive tasks, the time course of skeletal muscle Po2 is during recovery from contractions remains unknown. We tested the hypothesis that Po2 is would recover to resting values and display considerable on-off asymmetry (fast on-, slow off-kinetics), reflective of asymmetric capillary hemodynamics. Microvascular Po2 (Po2 mv) was also evaluated to test the hypothesis that a significant transcapillary gradient (ΔPo2 = Po2 mv - Po2 is) would be sustained during recovery. Po2 mv and Po2 is (expressed in mmHg) were determined via phosphorescence quenching in the exposed rat spinotrapezius muscle during and after submaximal twitch contractions (n = 12). Po2 is rose exponentially (P < 0.05) from end-contraction (11.1 ± 5.1), such that the end-recovery value (17.9 ± 7.9) was not different from resting Po2 is (18.5 ± 8.1; P > 0.05). Po2 is off-kinetics were slower than on-kinetics (mean response time: 53.1 ± 38.3 versus 18.5 ± 7.3 s; P < 0.05). A significant transcapillary ΔPo2 observed at end-contraction (16.6 ± 7.4) was maintained throughout recovery (end-recovery: 18.8 ± 9.6; P > 0.05). Consistent with our hypotheses, muscle Po2 is recovered to resting values with slower off-kinetics compared with the on-transient in line with the on-off asymmetry for capillary hemodynamics. Maintenance of a substantial transcapillary ΔPo2 during recovery supports that the microvascular-interstitium interface provides considerable resistance to O2 transport. As dictated by Fick's law (V̇o2 = Do2 × ΔPo2), modulation of O2 flux (V̇o2) during recovery must be achieved via corresponding changes in effective diffusing capacity (Do2; mainly capillary red blood cell hemodynamics and distribution) in the face of unaltered ΔPo2.NEW & NOTEWORTHY Capillary blood-myocyte O2 flux (V̇o2) is determined by effective diffusing capacity (Do2; mainly erythrocyte hemodynamics and distribution) and microvascular-interstitial Po2 gradients (ΔPo2 = Po2 mv - Po2 is). We show that Po2 is demonstrates on-off asymmetry consistent with Po2 mv and erythrocyte kinetics during metabolic transitions. A substantial transcapillary ΔPo2 was preserved during recovery from contractions, indicative of considerable resistance to O2 diffusion at the microvascular-interstitium interface. This reveals that effective Do2 declines in step with V̇o2 during recovery, as per Fick's law.
Scientific journal, English

Regional differences in Ca2+ entry along the proximal-middle-distal muscle axis during eccentric contractions in rat skeletal muscle.
Ayaka Tabuchi; Hiroaki Eshima; Yoshinori Tanaka; Shunsuke Nogami; Naoki Inoue; Mizuki Sudo; Hidetaka Okada; David C. Poole; Yutaka Kano
Corresponding, Journal of Applied Physiology, The American Physiological Society (APS), 127, 3, 828-837, 01 Sep. 2019, Peer-reviwed, True, Eccentric (ECC) contraction-induced muscle damage is associated with calcium ion (Ca2+) influx from the extracellular milieu through stretch-activated channels. It remains unknown whether Ca2+ influx consequent to repetitive ECC contractions is nonuniform across different muscle regions. We tested the hypothesis that there are regional differences in Ca2+ entry along the proximal-middle-distal muscle axis. Tibialis anterior (TA) muscles of adult male Wistar rats were exposed by reflecting the overlying skin and fasciae and ECC contractions evoked by peroneal nerve stimulation paired with simultaneous ankle extension (50 times/set, 2 protocols: 1 set and 10 sets). During ECC in the proximal, middle, and distal TA, we determined 1) muscle fiber extension by high-speed camera (200 frames/s) and 2) Ca2+ accumulation by in vivo bioimaging (Ca2+-sensitive probe Fura-2-acetoxymethyl ester). Muscle fiber extension from resting was significantly different among regions (i.e., proximal, 4.0%: < middle, 11.2%: < distal, 17.0%; ECC phase length at 500th contraction). Intracellular Ca2+ accumulation after 1 set of ECC was higher in the distal (1.46 ± 0.04, P < 0.05) than the proximal (1.27 ± 0.04) or middle (1.26 ± 0.05) regions. However, this regional Ca2+ accumulation difference disappeared by 32.5 min after the 1 set protocol when the muscle was quiescent and by contraction set 5 for the 10-set protocol. The initial preferential ECC-induced Ca2+ accumulation observed distally was associated spatially with the greater muscle extension compared with that of the proximal and middle regions. Disappearance of the regional Ca2+ accumulation disparity in quiescent and ECC-contracting muscle might be explained, in part, by axial Ca2+ propagation and account for the uniformity of muscle damage across regions evident 3 days post-ECC.NEW & NOTEWORTHY After 1 set of 50 eccentric (ECC) contractions in the anterior tibialis muscle, intracellular Ca2+ ([Ca2+]i) accumulation evinces substantial regional heterogeneity that is spatially coherent with muscle length changes (i.e., distal [Ca2+]i > middle, proximal). However, irrespective of whether 50 or 500 ECC contractions are performed, this heterogeneity is subsequently abolished, at least in part, by axial intracellular Ca2+ propagation. This Ca2+ homogenization across regions is consistent with the absence of any interregional difference in muscle damage 3 days post-ECC.
Scientific journal, English

Skeletal muscle interstitial O2 pressures: bridging the gap between the capillary and myocyte.
Daniel M. Hirai; Trenton D. Colburn; Jesse C. Craig; Kazuki Hotta; Yutaka Kano; Timothy I. Musch; David C. Poole
Microcirculation, 26, 5, e12497, 01 Jul. 2019, Peer-reviwed
Scientific journal, English

Accumulation of intramyocyte TRPV1-mediated calcium during heat stress is inhibited by concomitant muscle contractions.
Ryo Ikegami; Hiroaki Eshima; Takuro Mashio; Tomosada Ishiguro; Daisuke Hoshino; David C Poole; Yutaka Kano
Corresponding, Journal of Applied Physiology (Bethesda, Md. : 1985), 126, 3, 691-698, 01 Mar. 2019, Peer-reviwed, True, Heat stress promotes intramyocyte calcium concentration ([Ca2+]i) accumulation via transient receptor potential vanilloid 1 (TRPV1) channels. We tested the hypothesis that muscle contractile activity concomitant with heat stress would accelerate the increase in [Ca2+]i via TRPV1, further impairing [Ca2+]i homeostasis. Spinotrapezius muscles of adult Wistar rats were exteriorized in vivo and loaded with the fluorescent Ca2+ probe fura 2-AM. Heat stress (muscle surface temperature 40°C) was used as TRPV1 activator. An isometric contraction (100 Hz, 5-10 V, 30 s) was induced electrically concomitant with heat stress. [Ca2+]i was determined for 20 min using in vivo fluorescence microscopy, and the phosphorylation response of TRPV1 was determined by Western blotting. Heat stress induced a significant [Ca2+]i increase of 18.5 ± 8.1% at 20 min and TRPV1 phosphorylation (+231%), which was inhibited by addition of the TRPV1 inhibitor (capsazepine). However, contrary to expectations, the heat stress and isometric contraction condition almost completely inhibited TRPV1 phosphorylation and the consequent [Ca2+]i elevation (<2.8% accumulation during heat stress, P > 0.05). In conclusion, this in vivo physiological model demonstrated that isometric muscle contraction(s) can suppress the phosphorylation response of TRPV1 and maintain [Ca2+]i homeostasis during heat stress. NEW & NOTEWORTHY This investigation is the first document the dynamics of intramyocyte calcium concentration ([Ca2+]i) increase in the myoplasm of skeletal muscle fibers in response to heat stress where the muscle blood flow is preserved. Heat stress at 40°C drives a myoplasmic [Ca2+]i accumulation in concert with transient receptor potential vanilloid 1 (TRPV1) phosphorylation. However, muscle contraction caused TRPV1 channel deactivation by dephosphorylation of TRPV1. TRPV1 inactivation via isometric contraction(s) permits maintenance of [Ca2+]i homeostasis even under high imposed muscle temperature.
Scientific journal, English

Microvascular Permeability of Skeletal Muscle After Eccentric Contraction-Induced Muscle Injury: In Vivo Imaging Using Two-Photon Laser Scanning Microscopy.
Kazuki Hotta; Bradley Behnke; Kazuto Masamoto; Rie Shimotsu; Naoya Onodera; Akihiko Yamaguchi; David Poole; Yutaka Kano
Corresponding, Journal of Applied Physiology, 125, 2, 369-380, 01 Aug. 2018, Peer-reviwed, True, Via modulation of endothelial integrity and vascular permeability in response to damage, skeletal muscle microvessels play a crucial permissive role in tissue leukocyte invasion. However, direct visual evidence of altered microvascular permeability of skeletal muscle has not been technically feasible, impairing mechanistic understanding of these responses. Two-photon laser scanning microscopy (TPLSM) allows three-dimensional in vivo imaging of skeletal muscle microcirculation. We hypothesized that the regulation of microvascular permeability in vivo is temporally related to acute inflammatory and regenerative processes following muscle injury. To test our hypothesis, tibialis anterior muscles of anesthetized male Wistar rats were subjected to eccentric contractions (ECCs) via electrical stimulation. The skeletal muscle microcirculation was imaged by an intravenously infused fluorescent dye (rhodamine B isothiocyanate-dextran) to assess microvascular permeability via TPLSM 1, 3, and 7 days after ECC. Immunohistochemistry on serial muscle sections was performed to determine the proportion of VEGF-A-positive muscle fibers in the damaged muscle. Compared with control rats, the volumetrically determined interstitial leakage of fluorescent dye (5.1 ± 1.4, 5.3 ± 1.2 vs. 0.51 ± 0.14 μm3 × 106; P < 0.05, days 1 and 3, respectively, vs. control) and percentage of VEGF-A-positive fibers in the damaged muscle (10 ± 0.4%, 22 ± 1.1% vs. 0%; days 1 and 3, respectively, vs. control) were significantly higher on days 1 and 3 after ECC. The interstitial leakage volume returned to control by day 7. These results suggest that microvascular hyperpermeability assessed by in vivo TPLSM imaging is associated with ECC-induced muscle damage and increased VEGF expression. NEW & NOTEWORTHY This investigation employed a novel in vivo imaging technique for skeletal muscle microcirculation using two-photon laser scanning microscopy that enabled microvascular permeability to be assessed by four-dimensional image analysis. By combining in vivo imaging and histological analysis, we found the temporal profile of microvascular hyperpermeability to be related to that of eccentric contraction-induced skeletal muscle injury and pronounced novel myocyte VEGF expression.
Scientific journal, English

Mitochondrial calcium regulation during and following contractions in skeletal muscle.
Hiroaki Eshima; David Poole; Yutaka Kano
Corresponding, The Journal of Physical Fitness and Sports Medicine (JPFSM)., 7, 4, 205-211, 25 Jul. 2018, Peer-reviwed
Scientific journal, English

Muscle hypertrophy following blood flow-restricted, low-force isometric electrical stimulation in rat tibialis anterior: role for muscle hypoxia.
Toshiaki Nakajima; Seiichiro Koide; Tomohiro Yasuda; Takaaki Hasegawa; Tatsuya Yamasoba; Syotaro Obi; Shigeru Toyoda; Fumitaka Nakamura; Teruo Inoue; David C Poole; Yutaka Kano
Corresponding, Journal of Applied Physiology (Bethesda, Md. : 1985), 125, 1, 134-145, 01 Jul. 2018, Peer-reviwed, True, Low-force exercise training with blood flow restriction (BFR) elicits muscle hypertrophy as seen typically after higher-force exercise. We investigated the effects of microvascular hypoxia [i.e., low microvascular O2 partial pressures (P mvO2)] during contractions on muscle hypertrophic signaling, growth response, and key muscle adaptations for increasing exercise capacity. Wistar rats were fitted with a cuff placed around the upper thigh and inflated to restrict limb blood flow. Low-force isometric contractions (30 Hz) were evoked via electrical stimulation of the tibialis anterior (TA) muscle. The P mvO2 was determined by phosphorescence quenching. Rats underwent acute and chronic stimulation protocols. Whereas P mvO2 decreased transiently with 30 Hz contractions, simultaneous BFR induced severe hypoxia, reducing P mvO2 lower than present for maximal (100 Hz) contractions. Low-force electrical stimulation (EXER) induced muscle hypertrophy (6.2%, P < 0.01), whereas control group conditions or BFR alone did not. EXER+BFR also induced an increase in muscle mass (11.0%, P < 0.01) and, unique among conditions studied, significantly increased fiber cross-sectional area in the superficial TA ( P < 0.05). Phosphorylation of ribosomal protein S6 was enhanced by EXER+BFR, as were peroxisome proliferator-activated receptor gamma coactivator-1α and glucose transporter 4 protein levels. Fibronectin type III domain-containing protein 5, cytochrome c oxidase subunit 4, monocarboxylate transporter 1 (MCT1), and cluster of differentiation 147 increased with EXER alone. EXER+BFR significantly increased MCT1 expression more than EXER alone. These data demonstrate that microvascular hypoxia during contractions is not essential for hypertrophy. However, hypoxia induced via BFR may potentiate the muscle hypertrophic response (as evidenced by the increased superficial fiber cross-sectional area) with increased glucose transporter and mitochondrial biogenesis, which contributes to the pleiotropic effects of exercise training with BFR that culminate in an improved capacity for sustained exercise. NEW & NOTEWORTHY We investigated the effects of low microvascular O2 partial pressures (P mvO2) during contractions on muscle hypertrophic signaling and key elements in the muscle adaptation for increasing exercise capacity. Although demonstrating that muscle hypoxia is not obligatory for the hypertrophic response to low-force, electrically induced muscle contractions, the reduced P mvO2 enhanced ribosomal protein S6 phosphorylation and potentiated the hypertrophic response. Furthermore, contractions with blood flow restriction increased oxidative capacity, glucose transporter, and mitochondrial biogenesis, which are key determinants of the pleiotropic effects of exercise training.
Scientific journal, English

Skeletal muscle microvascular and interstitial PO 2 from rest to contractions
Daniel M. Hirai; Jesse C. Craig; Trenton D. Colburn; Hiroaki Eshima; Yutaka Kano; William L. Sexton; Timothy I. Musch; David C. Poole
Journal of Physiology, Blackwell Publishing Ltd, 596, 5, 869-883, 01 Mar. 2018, Peer-reviwed, Key points: Oxygen pressure gradients across the microvascular walls are essential for oxygen diffusion from blood to tissue cells. At any given flux, the magnitude of these transmural gradients is proportional to the local resistance. The greatest resistance to oxygen transport into skeletal muscle is considered to reside in the short distance between red blood cells and myocytes. Although crucial to oxygen transport, little is known about transmural pressure gradients within skeletal muscle during contractions. We evaluated oxygen pressures within both the skeletal muscle microvascular and interstitial spaces to determine transmural gradients during the rest–contraction transient in anaesthetized rats. The significant transmural gradient observed at rest was sustained during submaximal muscle contractions. Our findings support that the blood–myocyte interface provides substantial resistance to oxygen diffusion at rest and during contractions and suggest that modulations in microvascular haemodynamics and red blood cell distribution constitute primary mechanisms driving increased transmural oxygen flux with contractions. Abstract: Oxygen pressure ((Formula presented.)) gradients across the blood–myocyte interface are required for diffusive O2 transport, thereby supporting oxidative metabolism. The greatest resistance to O2 flux into skeletal muscle is considered to reside between the erythrocyte surface and adjacent sarcolemma, although this has not been measured during contractions. We tested the hypothesis that O2 gradients between skeletal muscle microvascular ((Formula presented.)) and interstitial ((Formula presented.)) spaces would be present at rest and maintained or increased during contractions. (Formula presented.) and (Formula presented.) were determined via phosphorescence quenching (Oxyphor probes G2 and G4, respectively) in the exposed rat spinotrapezius during the rest–contraction transient (1 Hz, 6 V
n = 8). (Formula presented.) was higher than (Formula presented.) in all instances from rest (34.9 ± 6.0 versus 15.7 ± 6.4) to contractions (28.4 ± 5.3 versus 10.6 ± 5.2 mmHg, respectively) such that the mean (Formula presented.) gradient throughout the transient was 16.9 ± 6.6 mmHg (P <
 0.05 for all). No differences in the amplitude of (Formula presented.) fall with contractions were observed between the microvasculature and interstitium (10.9 ± 2.3 versus 9.0 ± 3.5 mmHg, respectively
P >
 0.05). However, the speed of the (Formula presented.) fall during contractions was slower than that of (Formula presented.) (time constant: 12.8 ± 4.7 versus 9.0 ± 5.1 s, respectively
P <
 0.05). Consistent with our hypothesis, a significant transmural gradient was sustained (but not increased) from rest to contractions. This supports that the blood–myocyte interface is the site of a substantial (Formula presented.) gradient driving O2 diffusion during metabolic transients. Based on Fick's law, elevated O2 flux with contractions must thus rely primarily on modulations in effective diffusing capacity (mainly erythrocyte haemodynamics and distribution) as the (Formula presented.) gradient is not increased.
Scientific journal, English

The effects of RSR13 on microvascular PO2 kinetics and muscle contractile performance in the rat arterial ligation model of peripheral arterial disease
Aiko Watanabe; David C. Poole; Yutaka Kano
Corresponding, Journal of Applied Physiology, AMER PHYSIOLOGICAL SOC, 123, 4, 764-772, Oct. 2017, Peer-reviwed, Exercise intolerance and claudication are symptomatic of peripheral arterial disease. There is a close relationship between muscle O-2 delivery, microvascular oxygen partial pressure (PmvO(2)), and contractile performance. We therefore hypothesized that a reduction of hemoglobin-oxygen affinity via RSR13 would maintain a higher PmvO(2) and enhance blood-muscle O-2 transport and contractile function. In male Wistar rats (12 wk of age), we created hindlimb ischemia via right-side iliac artery ligation (AL). The contralateral (left) muscle served as control (CONT). Seven days after AL, phosphorescence-quenching techniques were used to measure PmvO(2) at rest and during contractions (electrical stimulation; 1 Hz, 300 s) in tibialis anterior muscle (TA) under saline (n = 10) or RSR13 (n = 10) conditions. RSR13 at rest increased TA PmvO(2) in CONT (13.9 +/- 1.6 to 19.3 +/- 1.9 Torr, P < 0.05) and AL (9.0 +/- 0.5 to 9.9 +/- 0.7 Torr, P < 0.05). Furthermore, RSR13 extended maintenance of the initial TA force (i.e., improved contractile performance) such that force was not decreased significantly until contraction 240 vs. 150 in CONT and 80 vs. 20 in AL. This improved muscle endurance with RSR13 was accompanied by a greater Delta PmvO(2) (PmvO(2) decrease from baseline) (CONT, 7.4 +/- 1.0 to 11.2 +/- 1.3; AL, 6.9 +/- 0.5 to 8.6 +/- 0.6 Torr, both P < 0.05). Whereas RSR13 did not alter the kinetics profile of PmvO(2) (i.e., mean response time) substantially during contractions, muscle force was elevated, and the ratio of muscle force to PmvO(2) increased. In conclusion, reduction of hemoglobin-oxygen affinity via RSR13 in AL increased PmvO(2) and improved muscle contractile performance most likely via enhanced blood-muscle O-2 diffusion.
NEW & NOTEWORTHY This is the first investigation to examine the effect of RSR13 (erythrocyte allosteric effector) on skeletal muscle microvascular oxygen partial pressure kinetics and contractile function using an arterial ligation model of peripheral arterial disease in experimental animals. The present results provide strong support for the concept that reducing hemoglobin-O-2 affinity via RSR13 improved tibialis anterior muscle contractile performance most likely via enhanced blood-muscle O-2 diffusion.
Scientific journal, English

Photothermal imaging of skeletal muscle mitochondria
Toru Tomimatsu; Jun Miyazaki; Yutaka Kano; Takayoshi Kobayashi
Biomedical Optics Express, OPTICAL SOC AMER, 8, 6, 2965-2975, Jun. 2017, Peer-reviwed, The morphology and topology of mitochondria provide useful information about the physiological function of skeletal muscle. Previous studies of skeletal muscle mitochondria are based on observation with transmission, scanning electron microscopy or fluorescence microscopy. In contrast, photothermal (PT) microscopy has advantages over the above commonly used microscopic techniques because of no requirement for complex sample preparation by fixation or fluorescent-dye staining. Here, we employed the PT technique using a simple diode laser to visualize skeletal muscle mitochondria in unstained and stained tissues. The fine mitochondrial network structures in muscle fibers could be imaged with the PT imaging system, even in unstained tissues. PT imaging of tissues stained with toluidine blue revealed the structures of subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria and the swelling behavior of mitochondria in damaged muscle fibers with sufficient image quality. PT image analyses based on fast Fourier transform (FFT) and Grey-level co-occurrence matrix (GLCM) were performed to derive the characteristic size of mitochondria and to discriminate the image patterns of normal and damaged fibers. (C) 2017 Optical Society of America
Scientific journal, English

Improved skeletal muscle Ca2+ regulation in vivo following contractions in mice overexpressing PGC-1 alpha
Hiroaki Eshima; Shinji Miura; Nanami Senoo; Koji Hatakeyama; David C. Poole; Yutaka Kano
Corresponding, AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, AMER PHYSIOLOGICAL SOC, 312, 6, R1017-R1028, Jun. 2017, Peer-reviwed, In skeletal muscle, resting intracellular Ca2+ concentration ([ Ca2+]i) homeostasis is exquisitely regulated by Ca2+ transport across the sarcolemmal, mitochondrial, and sarcoplasmic reticulum (SR) membranes. Of these three systems, the relative importance of the mitochondria in [ Ca2+] i regulation remains poorly understood in in vivo skeletal muscle. We tested the hypothesis that the capacity for Ca2+ uptake by mitochondria is a primary factor in determining [ Ca2+] i regulation in muscle at rest and following contractions. Tibialis anterior muscle of anesthetized peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1 alpha)-overexpressing (OE, increased mitochondria model) and wild-type (WT) littermate mice was exteriorized in vivo and loaded with the fluorescent probe fura 2-AM, and Rhod 2-AM Ca2+ buffering and mitochondrial [ Ca2+] were evaluated at rest and during recovery from fatiguing tetanic contractions induced by electrical stimulation (120 s, 100 Hz). In addition, the effects of pharmacological inhibition of SR (thapsigargin) and mitochondrial [ carbonyl cyanide-4-(trifluoromethoxy) phenylhydrazone (FCCP)] function were examined at rest. [ Ca2+] i in WT remained elevated for the entire postcontraction recovery period (+6 +/- 1% at 450 s), but in PGC-1 alpha OE [ Ca2+] i returned to resting baseline within 150 s. Thapsigargin immediately and substantially increased resting [ Ca2+] i in WT, whereas in PGC-1 alpha OE this effect was delayed and markedly diminished (WT, +12 +/- 3; PGC-1 alpha OE, + 1 +/- 2% at 600 s after thapsigargin treatment, P < 0.05). FCCP abolished this improvement of [ Ca2+] i regulation in PGC-1 alpha OE. Mitochondrial [ Ca2+] accumulation was observed in PGC-1 alpha OE following contractions and thapsigargin treatment. In the SR, PGC-1 alpha OE downregulated SR Ca2+ ATPase 1 (Ca2+ uptake) and parvalbumin (Ca2+ buffering) protein levels, whereas mitochondrial Ca2+ uptake-related proteins (Mfn1, Mfn2, and mitochondrial Ca2+ uniporter) were upregulated. These data demonstrate a heretofore unappreciated role for skeletal muscle mitochondria in [ Ca2+] i regulation in vivo following fatiguing tetanic contractions and at rest.
Scientific journal, English

In vivo Ca2+ dynamics induced by Ca2+ injection in individual rat skeletal muscle fibers
Mario Wakizaka; Hiroaki Eshima; Yoshinori Tanaka; Hideki Shirakawa; David C. Poole; Yutaka Kano
Corresponding, Physiological Reports, American Physiological Society, 5, 5, e13180, 01 Mar. 2017, Peer-reviwed, In contrast to cardiomyocytes, store overload-induced calcium ion (Ca2+) release (SOICR) is not considered to constitute a primary Ca2+ releasing system from the sarcoplasmic reticulum (SR) in skeletal muscle myocytes. In the latter, voltage-induced Ca2+ release (VICR) is regarded as the dominant mechanism facilitating contractions. Any role of the SOICR in the regulation of cytoplasmic Ca2+ concentration ([Ca2+]i) and its dynamics in skeletal muscle in vivo remains poorly understood. By means of in vivo single fiber Ca2+ microinjections combined with bioimaging techniques, we tested the hypothesis that the [Ca2+]i dynamics following Ca2+ injection would be amplified and fiber contraction facilitated by SOICR. The circulation-intact spinotrapezius muscle of adult male Wistar rats (n = 34) was exteriorized and loaded with Fura-2 AM to monitor [Ca2+]i dynamics. Groups of rats underwent the following treatments: (1) 0.02, 0.2, and 2.0 mmol/L Ca2+ injections, (2) 2.0 mmol/L Ca2+ with inhibition of ryanodine receptors (RyR) by dantrolene sodium (DAN), and (3) 2.0 mmol/L Ca2+ with inhibition of SR Ca2+ ATPase (SERCA) by cyclopiazonic acid (CPA). A quantity of 0.02 mmol/L Ca2+ injection yielded no detectable response, whereas peak evoked [Ca2+]i increased 9.9 ± 1.8% above baseline for 0.2 mmol/L and 23.8 ± 4.3% (P <
 0.05) for 2.0 mmol/L Ca2+ injections. The peak [Ca2+]i in response to 2.0 mmol/L Ca2+ injection was largely abolished by DAN and CPA (−85.8%, −71.0%, respectively, both P <
 0.05 vs. unblocked) supporting dependence of the [Ca2+]i dynamics on Ca2+ released by SOICR rather than injected Ca2+ itself. Thus, this investigation demonstrates the presence of a robust SR-evoked SOICR operant in skeletal muscle in vivo.
Scientific journal, English

Repeated blood flow restriction induces muscle fiber hypertrophy
Mizuki Sudo; Soichi Ando; Yutaka Kano
Corresponding, Muscle & Nerve, WILEY, 55, 2, 274-276, Feb. 2017, Peer-reviwed, IntroductionWe recently developed an animal model to investigate the effects of eccentric contraction (ECC) and blood flow restriction (BFR) on muscle tissue at the cellular level. This study clarified the effects of repeated BFR, ECC, and BFR combined with ECC (BFR+ECC) on muscle fiber hypertrophy.
MethodsMale Wistar rats were assigned to 3 groups: BFR, ECC, and BFR+ECC. The contralateral leg in the BFR group served as a control (CONT). Muscle fiber cross-sectional area (CSA) of the tibialis anterior was determined after the respective treatments for 6 weeks.
ResultsCSA was greater in the BFR+ECC group than in the CONT (P<0.01) and ECC (P<0.05) groups. CSA was greater in the BFR group than that in the CONT group (P<0.05).
CnclusionsThese results suggest that repeated BFR alone as well as BFR+ECC induces muscle fiber hypertrophy at the cellular level. Muscle Nerve55: 274-276, 2017
Scientific journal, English

Repetitive restriction of muscle blood flow enhances mTOR signaling pathways in a rat model
Toshiaki Nakajima; Tomohiro Yasuda; Seiichiro Koide; Tatsuya Yamasoba; Syotaro Obi; Shigeru Toyoda; Yoshiaki Sato; Teruo Inoue; Yutaka Kano
Heart And Vessels, SPRINGER, 31, 10, 1685-1695, Oct. 2016, Peer-reviwed, Skeletal muscle is a plastic organ that adapts its mass to various stresses by affecting pathways that regulate protein synthesis and degradation. This study investigated the effects of repetitive restriction of muscle blood flow (RRMBF) on microvascular oxygen pressure (PmvO(2)), mammalian target of rapamycin (mTOR) signaling pathways, and transcripts associated with proteolysis in rat skeletal muscle. Eleven-week-old male Wistar rats under anesthesia underwent six RRMBF consisting of an external compressive force of 100 mmHg for 5 min applied to the proximal portion of the right thigh, each followed by 3 min rest. During RRMBF, PmvO(2) was measured by phosphorescence quenching techniques. The total RNA and protein of the tibialis anterior muscle were obtained from control rats, and rats treated with RRMBF 0-6 h after the stimuli. The protein expression and phosphorylation of various signaling proteins were determined by western blotting. The mRNA expression level was measured by real-time RT-PCR analysis. The total muscle weight increased in rats 0 h after RRMBF, but not in rats 1-6 h. During RRMBF, PmvO(2) significantly decreased (36.1 +/- 5.7 to 5.9 +/- 1.7 torr), and recovered at rest period. RRMBF significantly increased phosphorylation of p70 S6-kinase (p70S6k), a downstream target of mTOR, and ribosomal protein S6 1 h after the stimuli. The protein level of REDD1 and phosphorylation of AMPK and MAPKs did not change. The mRNA expression levels of FOXO3a, MuRF-1, and myostatin were not significantly altered. These results suggested that RRMBF significantly decreased PmvO(2), and enhanced mTOR signaling pathways in skeletal muscle using a rat model, which may play a role in diminishing muscle atrophy under various conditions in human studies.
Scientific journal, English

pH buffering of single rat skeletal muscle fibers in the in vivo environment
Yoshinori Tanaka; Tadakatsu Inagaki; David C. Poole; Yutaka Kano
Corresponding, American Journal of Physiology-Regulatory Integrative and Comparative Physiology, AMER PHYSIOLOGICAL SOC, 310, 10, R926-R933, May 2016, Peer-reviwed, Homeostasis of intracellular pH (pH(i)) has a crucial role for the maintenance of cellular function. Several membrane transporters such as lactate/H+ cotransporter (MCT), Na+/H+ exchange transporter (NHE), and Na+/HCO3- cotransporter (NBC) are thought to contribute to pH(i) regulation. However, the relative importance of each of these membrane transporters to the in vivo recovery from the low pH(i) condition is unknown. Using an in vivo bioimaging model, we pharmacologically inhibited each transporter separately and all transporters together and then evaluated the pH(i) recovery profiles following imposition of a discrete H+ challenge loaded into single muscle fibers by microinjection. The intact spinotrapezius muscle of adult male Wistar rats (n = 72) was exteriorized and loaded with the fluorescent probe 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein-acetoxymethyl ester (10 mu M). A single muscle fiber was then loaded with low-pH solution [piperazine-N,N=-bis(2-ethane-sulfonic acid) buffer, pH 6.5, similar to 2.33 x 10(-3) mu l] by microinjection over 3 s. The rats were divided into groups for the following treatments: 1) no inhibitor (CONT), 2) MCT inhibition (by alpha-Cyano-4-hydroxyciannamic acid; 4 mM), 3) NHE inhibition (by ethylisopropyl amiloride; 0.5 mM), 4) NBC inhibition (by DIDS; 1 mM), and 5) MCT, NHE, and NBC inhibition (All blockade). The fluorescence ratio (F500 nm/F445 nm) was determined from images captured during 1 min (60 images/min) and at 5, 10, 15, and 20 min after injection. The pH(i) at 1-2 s after injection significantly decreased from resting pH(i) (Delta pH(i) = -0.73 +/- 0.03) in CONT. The recovery response profile was biphasic, with an initial rapid and close-to-exponential pH(i) increase (time constant, tau : 60.0 +/- 7.9 s). This initial rapid profile was not affected by any pharmacological blockade but was significantly delayed by carbonic anhydrase inhibition. In contrast, the secondary, more gradual, return toward baseline that restored CONT pH(i) to 84.2% of baseline was unimpeded by MCT, NHE, and NBC blockade separately but abolished by All blockade (Delta pH(i) = -0.60 +/- 0.07, 72.8% initial pH(i), P < 0.05 vs. CONT). After injection of H+ into, or superfusion onto, an adjacent fiber pHi of the surrounding fibers decreased progressively for the 20-min observation period (similar to 7.0, P < 0.05 vs. preinjection/superfusion). In conclusion, these results support that, after an imposed H+ load, the MCT, NHE, and NBC transporters are not involved in the initial rapid phase of pH(i) recovery. In contrast, the gradual recovery phase was abolished by inhibiting all three membrane transporter systems simultaneously. The alteration of pH(i) in surrounding fibers suggest that H+ uptake by neighboring fibers can help alleviate the pH consequences of myocyte H+ exudation.
Scientific journal, English

pH Homeostasis in Contracting and Recovering Skeletal Muscle: Integrated Function of the Microcirculation with the Interstitium and Intramyocyte Milieu
Yoshinori Tanaka; David C. Poole; Yutaka Kano
Corresponding, Current Topics in Medicinal Chemistry, BENTHAM SCIENCE PUBL LTD, 16, 24, 2656-2663, 2016, Peer-reviwed, Skeletal muscle contractions and their attendant increase in metabolism accelerate production and accumulation of multiple metabolites in the cytoplasm, interstitium and vascular compartments. Continued myocyte contractile function and subsequent recovery is often highly dependent upon constraining metabolite accumulation. In particular, the control of pH ([H+]) during exercise is absolutely crucial for muscle force maintenance and metabolic regulation. This short review focuses attention on the dynamic control mechanisms that help regulate H+ and thus intramyocyte pH (pHi) during muscle contractions: Specifically 1. Myocyte H+ production and intrinsic buffering systems, 2. Mechanisms of myocyte H+ excretion, and 3. Inter-relationships among the intramyocyte - interstitial - blood [H+].
Scientific journal, English

Microvascular oxygen partial pressure during hyperbaric oxygen in diabetic rat skeletal muscle
Kohei Yamakoshi; Kazuyoshi Yagishita; Hirotsugu Tsuchimochi; Tadakatsu Inagaki; Mikiyasu Shirai; David C. Poole; Yutaka Kano
Corresponding, American Journal of Physiology-Regulatory Integrative and Comparative Physiology, AMER PHYSIOLOGICAL SOC, 309, 12, R1512-R1520, Dec. 2015, Peer-reviwed, Hyperbaric oxygen (HBO) is a major therapeutic treatment for ischemic ulcerations that perforate skin and underlying muscle in diabetic patients. These lesions do not heal effectively, in part, because of the hypoxic microvascular O-2 partial pressures (PmvO(2)) resulting from diabetes-induced cardiovascular dysfunction, which alters the dynamic balance between O-2 delivery ((Q) over dotO(2)) and utilization ((V) over dotO(2)) rates. We tested the hypothesis that HBO in diabetic muscle would exacerbate the hyperoxic PmvO(2) dynamics due, in part, to a reduction or slowing of the cardiovascular, sympathetic nervous, and respiratory system responses to acute HBO exposure. Adult male Wistar rats were divided randomly into diabetic (DIA: streptozotocin ip) and healthy (control) groups. A small animal hyperbaric chamber was pressurized with oxygen (100% O-2) to 3.0 atmospheres absolute (ATA) at 0.2 ATA/min. Phosphorescence quenching techniques were used to measure PmvO(2) in tibialis anterior muscle of anesthetized rats during HBO. Lumbar sympathetic nerve activity (LSNA), heart rate (HR), and respiratory rate (RR) were measured electrophysiologically. During the normobaric hyperoxia and HBO, DIA tibialis anterior PmvO(2) increased faster (mean response time, CONT 78 +/- 8, DIA 55 +/- 8 s, P < 0.05) than CONT. Subsequently, PmvO(2) remained elevated at similar levels in CONT and DIA muscles until normobaric normoxic recovery where the DIA PmvO(2) retained its hyperoxic level longer than CONT. Sympathetic nervous system and cardiac and respiratory responses to HBO were slower in DIA vs. CONT. Specifically the mean response times for RR (CONT: 6 +/- 1 s, DIA: 29 +/- 4 s, P < 0.05), HR (CONT: 16 +/- 1 s, DIA: 45 +/- 5 s, P < 0.05), and LSNA (CONT: 140 +/- 16 s, DIA: 247 +/- 34 s, P < 0.05) were greater following HBO onset in DIA than CONT. HBO treatment increases tibialis anterior muscle PmvO(2) more rapidly and for a longer duration in DIA than CONT, but not to a greater level. Whereas respiratory, cardiovascular, and LSNA responses to HBO are profoundly slowed in DIA, only the cardiovascular arm (via HR) may contribute to the muscle vascular incompetence and these faster PmvO(2) kinetics.
Scientific journal, English

In vivo Ca2+ buffering capacity and microvascular oxygen pressures following muscle contractions in diabetic rat skeletal muscles: fiber-type specific effects
Hiroaki Eshima; David C. Poole; Yutaka Kano
Corresponding, American Journal of Physiology-Regulatory Integrative and Comparative Physiology, AMER PHYSIOLOGICAL SOC, 309, 2, R128-R137, Jul. 2015, Peer-reviwed, In Type 1 diabetes, skeletal muscle resting intracellular Ca2+ concentration ([Ca2+](i)) homeostasis is impaired following muscle contractions. It is unclear to what degree this behavior is contingent upon fiber type and muscle oxygenation conditions. We tested the hypotheses that: 1) the rise in resting [Ca2+](i) evident in diabetic rat slow-twitch (type I) muscle would be exacerbated in fast-twitch (type II) muscle following contraction; and 2) these elevated [Ca2+](i) levels would relate to derangement of microvascular partial pressure of oxygen (Pmv(O2)) rather than sarcoplasmic reticulum dysfunction per se. Adult male Wistar rats were divided randomly into diabetic (DIA: streptozotocin ip) and healthy (CONT) groups. Four weeks later extensor digitorum longus (EDL, predominately type II fibers) and soleus (SOL, predominately type I fibers) muscle contractions were elicited by continuous electrical stimulation (120 s, 100 Hz). Ca2+ imaging was achieved using fura 2-AM in vivo (i.e., circulation intact). DIA increased fatigability in EDL (P < 0.05) but not SOL. In recovery, SOL [Ca2+](i) either returned to its resting baseline within 150 s (CONT 1.00 +/- 0.02 at 600 s) or was not elevated in recovery at all (DIA 1.03 +/- 0.02 at 600 s, P > 0.05). In recovery, EDL CONT [Ca2+](i) also decreased to values not different from baseline (1.06 +/- 0.01, P > 0.05) at 600 s. In marked contrast, EDL DIA [Ca2+](i) remained elevated for the entire recovery period (i.e., 1.23 +/- 0.03 at 600 s, P < 0.05). The inability of [Ca2+](i) to return to baseline in EDL DIA was not associated with any reduction of SR Ca2+ -ATPase (SERCA) 1 or SERCA2 protein levels (both increased 30-40%, P < 0.05). However, Pmv(O2) recovery kinetics were markedly slowed in EDL such that mean Pmv(O2) was substantially depressed (CONT 27.9 +/- 2.0 vs. DIA 18.4 +/- 2.0 Torr, P < 0.05), and this behavior was associated with the elevated [Ca2+](i). In contrast, this was not the case for SOL (P+ 0.05) in that neither [Ca2+](i) nor Pmv(O2) were deranged in recovery with DIA. In conclusion, recovery of [Ca2+](i) homeostasis is impaired in diabetic rat fast-twitch but not slow-twitch muscle in concert with reduced Pmv(O2) pressures.
Scientific journal, English

Blood flow restriction prevents muscle damage but not protein synthesis signaling following eccentric contractions
Mizuki Sudo; Soichi Ando; David C. Poole; Yutaka Kano
Corresponding, Physiological Reports, American Physiological Society, 3, 7, e12449, 2015, Peer-reviwed, There is a growing body of evidence to suggest that resistance training exercise combined with blood flow restriction (BFR) increases muscle size and strength in humans. Eccentric contraction (ECC) frequently induces severe muscle damage. However, it is not known whether and to what extent muscle damage occurs following ECC + BFR due to the difficulty of conducting definitive invasive studies. The purpose of this study was to examine muscle fiber damage following ECC + BFR at the cellular level. High-intensity ECC was purposefully selected to maximize the opportunity for muscle damage and hypertrophic signaling in our novel in vivo animal model. Male Wistar rats were assigned randomly to the following groups: ECC and ECC + BFR at varying levels of occlusion pressure (140, 160, and 200 Torr). In all conditions, electrical stimulation was applied to the dorsiflexor muscles simultaneously with electromotor- induced plantar flexion. We observed severe histochemical muscle fiber damage (area of damaged fibers/total fiber area analyzed) following ECC (26.4 � 4.0%). Surprisingly, however, muscle damage was negligible following ECC + BFR140 (2.6 � 1.2%), ECC+BFR160 (3.0 � 0.5%), and ECC + BFR200 (0.2 � 0.1%). Ribosomal S6 kinase 1 (S6K1) phosphorylation, a downstream target of rapamycin (mTOR)-phosphorylation kinase, increased following ECC + BFR200 as well as ECC. In contrast, S6K1 phosphorylation was not altered by BFR alone. The present findings suggest that ECC combined with BFR, even at high exercise intensities, may enhance muscle protein synthesis without appreciable muscle fiber damage.
Scientific journal, English

In vivo calcium regulation in diabetic skeletal muscle
Hiroaki Eshima; David C. Poole; Yutaka Kano
Corresponding, Cell Calcium, CHURCHILL LIVINGSTONE, 56, 5, 381-389, Nov. 2014, Peer-reviwed, Invited, In skeletal muscle, dysfunctional contractile activity has been linked to impaired intracellular Ca2+ concentration ([Ca2+](i)) regulation. Muscle force production is impaired and fatigability and muscle fragility deteriorate with diabetes. Use of a novel in vivo model permits investigation of [Ca2+](i) homeostasis in diabetic skeletal muscle. Within this in vivo environment we have shown that diabetes perturbs the Ca2+ regulatory system such that resting [Ca2+](i) homeostasis following muscle contractions is compromised and elevations of [Ca2+](i) are exacerbated. This review considers the impact of diabetes on the capacity of skeletal muscle to regulate [Ca2+](i), following muscle contractions and, in particular, the relationship between muscle fatigue and elevated [Ca2+](i) in a highly ecologically relevant circulation-intact environment. Importantly, the role of mitochondria in calcium sequestration and the possibility that diabetes impacts this process is explored. Given the profound microcirculatory dysfunction in diabetes this preparation offers the unique opportunity to study the interrelationships among microvascular function, blood-myocyte oxygen flux and [Ca2+]; as they relate to enhanced muscle fatigability and exercise intolerance. (C) 2014 Elsevier Ltd. All rights reserved.
Scientific journal, English

The effects of PGC-1 alpha on control of microvascular Po-2 kinetics following onset of muscle contractions
Yutaka Kano; Shinji Miura; Hiroaki Eshima; Osamu Ezaki; David C. Poole
Corresponding, JOURNAL OF APPLIED PHYSIOLOGY, AMER PHYSIOLOGICAL SOC, 117, 2, 163-170, Jul. 2014, Peer-reviwed, During contractions, regulation of microvascular oxygen partial pressure (Pmvo(2)), which drives blood-myocyte O-2 flux, is a function of skeletal muscle fiber type and oxidative capacity and can be altered by exercise training. The kinetics of Pmvo(2) during contractions in predominantly fast-twitch muscles evinces a more rapid fall to far lower levels compared with slow-twitch counterparts. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1 alpha) improves endurance performance, in part, due to mitochondrial biogenesis, a fiber-type switch to oxidative fibers, and angiogenesis in skeletal muscle. We tested the hypothesis that improvement of exercise capacity by genetic overexpression of PGC-1 alpha would be associated with an altered Pmvo(2) kinetics profile of the fast-twitch (white) gastrocnemius during contractions toward that seen in slow-twitch muscles (i.e., slowed response kinetics and elevated steady-state Pmvo(2)). Phosphorescence quenching techniques were used to measure Pmvo(2) at rest and during separate bouts of twitch (1 Hz) and tetanic (100 Hz) contractions in gastrocnemius muscles of mice with overexpression of PGC-1 alpha and wild-type littermates (WT) mice under isoflurane anesthesia. Muscles of PGC-1 alpha mice exhibited less fatigue than WT (P < 0.01). However, except for the Pmvo(2) response immediately following onset of contractions, WT and PGC-1 alpha mice demonstrated similar Pmvo(2) kinetics. Specifically, the time delay of the Pmvo(2) response was shortened in PGC-1 alpha mice compared with WT (1 Hz: WT, 6.6 +/- 2.4 s; PGC-1 alpha, 2.9 +/- 0.8 s; 100 Hz: WT, 3.3 +/- 1.1 s, PGC-1 alpha, 0.9 +/- 0.3 s, both P < 0.05). The ratio of muscle force to Pmvo(2) was higher for the duration of tetanic contractions in PGC-1 alpha mice. Slower dynamics and maintenance of higher Pmvo(2) following muscle contractions is not obligatory for improved fatigue resistance in fast-twitch muscle of PGC-1 alpha mice. Moreover, overexpression of PGC-1 alpha may accelerate O-2 utilization kinetics to a greater extent than O-2 delivery kinetics.
Scientific journal, English

In vivo imaging of intracellular Ca2+ after muscle contractions and direct Ca2+ injection in rat skeletal muscle in diabetes
Hiroaki Eshima; Yoshinori Tanaka; Takashi Sonobe; Tadakatsu Inagaki; Toshiaki Nakajima; David C. Poole; Yutaka Kano
Corresponding, American Journal of Physiology - Regulatory Integrative and Comparative Physiology, 305, 6, R610-R618, 15 Sep. 2013, Peer-reviwed, The effects of muscle contractions on the profile of postcontraction resting intracellular Ca2+ ([Ca2+]i) accumulation in Type 1 diabetes are unclear. We tested the hypothesis that, following repeated bouts of muscle contractions, the rise in resting [Ca2+]ievident in healthy rats would be increased in diabetic rats and that these changes would be associated with a decreased cytoplasmic Ca2+-buffering capacity. Adult male Wistar rats were divided randomly into diabetic (DIA
streptozotocin, ip) and healthy control (CONT) groups. Four weeks later, animals were anesthetized and spinotrapezius muscle contractions (10 sets of 50 contractions) were elicited by electrical stimulation (100 Hz). Ca2+ imaging was achieved using Fura-2 AM in the spinotrapezius muscle in vivo (i.e., circulation intact). The ratio (340/380 nm) was determined from fluorescence images following each set of contractions for estimation of [Ca2+]i. Also, muscle Ca2+ buffering was studied in individual myocytes microinjected with 2 mM Ca2+ solution. After muscle contractions, resting [Ca2+]i in DIA increased earlier and more rapidly than in CONT (P <
0.05 vs. precontraction). Peak [Ca2+]i in response to the Ca2+ injection was significantly higher in CONT (25.8 ± 6.0% above baseline) than DIA (10.2 ± 1.1% above baseline). Subsequently, CONT [Ca2+]i decreased rapidly (<
15 s) to plateau 9-10% above baseline, whereas DIA remained elevated throughout the 60-s measurement window. No differences in SERCA1 and SERCA2 (Ca2+ uptake) protein levels were evident between CONT and DIA, whereas ryanodine receptor (Ca2+ release) protein level and mitochondrial oxidative enzyme activity (succinate dehydrogenase) were decreased in DIA (P <
0.05). In conclusion, diabetes impairs resting [Ca2+]i homeostasis following muscle contractions. Markedly different responses to Ca2+ injection in DIA vs. CONT suggest fundamentally deranged Ca2+ handling. © 2013 the American Physiological Society.
Scientific journal, English

Role of nitric oxide in muscle regeneration following eccentric muscle contractions in rat skeletal muscle
Tomonobu Sakurai; Osamu Kashimura; Yutaka Kano; Hideki Ohno; Li Li Ji; Tetsuya Izawa; Thomas M. Best
Journal of Physiological Sciences, 63, 4, 263-270, Jul. 2013, Peer-reviwed, We examined the role of nitric oxide (NO) in muscle repair and regeneration following repetitive eccentric contractions (ECC). A standardized exercise protocol was used to create eccentric contraction-induced injury to the left tibialis anterior muscle of 48 male Wistar rats (body wt 250-350 g), using a customized isokinetic test device and a bout of 40 ECCs under electrical stimulation. A nitric oxide synthase inhibitor, N(G)-nitro-l-arginine-methyl ester (l-NAME
35 mg kg-1 day-1), was included in the diet for half the animals (n = 24) beginning 3 days prior to the ECC and continuing throughout the experiment, whereas the other half (n = 24) received a control diet. ECC/+l-NAME and ECC/-l-NAME were killed after the ECC protocol at 0, 1, 3 and 7 days (n = 6 on each day). An unexercised contralateral limb with and without l-NAME infusion served as a respective control muscle at each time point. Muscle NO content, skeletal muscle damage, leukocyte infiltration, calpain activity, and MyoD and myogenin expression were assessed. NO has both pro-inflammatory and anti-inflammatory properties, and several possible roles for NO in skeletal muscle damage have been postulated. NO content was greater in the ECC/-l-NAME group at all time points (p <
0.05) compared to ECC/+l-NAME. Additionally, significant differences in NO content were observed on day 0 (p <
0.05), and day 3 (p <
0.05), ECC/+l-NAME versus ECC/-l-NAME. One day following the bout of ECC, and NO levels were increased in the ECC/-l-NAME group. Three days following ECC, there was greater myofiber damage (measured by β-glucuronidase activity) and leukocyte invasion in the ECC/-l-NAME group as compared to the ECC/+l-NAME group. One day after ECC, calpain activity was significantly increased in ECC/-l-NAME compared with control muscles (p <
0.05). On days 3 and 7, Myo-D and myogenin gene expression was increased in both groups
however, the degree of regeneration was less in the ECC/+l-NAME-treated animals. These data suggest that NO dynamics have important implications in the regulation of various factors during skeletal muscle regeneration following damaging eccentric muscle contractions. © 2013 The Physiological Society of Japan and Springer Japan.
Scientific journal, English

In vivo imaging of intracellular Ca2+ after muscle contractions and direct Ca2+ injection in rat skeletal muscle in diabetes
Hiroaki Eshima; Yoshinori Tanaka; Takashi Sonobe; Tadakatsu Inagaki; David C. Poole; Yutaka Kano
Faseb journal, Federation amer soc exp biol, 27, Apr. 2013
English

Effect of aging on the relationship between capillary supply and muscle fiber size.
Yutaka Kano; Kunihiro Sakuma
Corresponding, Advances in Aging Research, 2, 1, 37-42, Feb. 2013, Peer-reviwed
Scientific journal, English

Mechanisms of exercise-induced muscle damage and fatigue: Intracellular calcium accumulation.
Yutaka Kano; Takashi Sonobe; Tadakatsu Inagaki; Mizuki Sudo; David C. Poole
Lead, The Journal of Physical Fitness and Sports Medicine (JPFSM), The Japanese Society of Physical Fitness and Sports Medicine, 1, 3, 505-512, 25 Sep. 2012, Peer-reviwed, Contraction-induced compromise of muscle function and, in the extreme, muscle damage has been linked to loss of Ca²⁺ homeostasis and resultant sustained elevation of intracellular Ca²⁺ ([Ca²⁺]_i). Against a background of in vitro approaches, a novel in vivo model permits investigation of the impact of different contraction types (e.g., isometric, ISO; eccentric, ECC) on [Ca²⁺]_i accumulation profiles. [Ca²⁺]_i elevation of ECC-contracted muscle is more rapid and greater in magnitude compared to ISO. Stretch-activated channels (SAC) are responsible, in large part, for this ECC contractions-induced [Ca²⁺]_i elevation. Transient Ca²⁺ accumulation in the cytosol incurs loss of force production, whereas continuous high levels of [Ca²⁺]_i, especially following ECC contractions, lead to muscle damage, including disrupted sarcomeres and membranes, and proceed, subsequently, to muscle regeneration via apoptosis and necrosis.
Scientific journal, English

Plasticity of microvascular oxygenation control in rat fast-twitch muscle: Effects of experimental creatine depletion
Paul McDonough; Danielle J. Padilla; Yutaka Kano; Timothy I. Musch; David C. Poole; Brad J. Behnke
Respiratory Physiology & Neurobiology, ELSEVIER SCIENCE BV, 181, 1, 14-20, Apr. 2012, Peer-reviwed, Aging, heart failure and diabetes each compromise the matching of O-2 delivery ((Q) over dot O-2)-to-metabolic requirements (O-2 uptake, (V) over dotO(2)) in skeletal muscle such that the O-2 pressure driving blood-myocyte O-2 flux (microvascular P02, PmvO(2)) is reduced and contractile function impaired. In contrast, p-guanidinopropionic acid (beta-CPA) treatment improves muscle contractile function, primarily in fasttwitch muscle (Moerland and Kushmerick, 1994). We tested the hypothesis that beta-CPA (2% wt/BW in rat chow, 8 weeks; n = 14) would improve ((Q) over dotO(2)-to-VO2 matching (elevated PmvO(2)) during contractions (4.5 V @1 Hz) in mixed (MG) and white (WG) portions of the gastrocnemius, both predominantly fast-twitch). Compared with control (CON), during contractions PmvO(2) fell less following beta-GPA (MG 54%, WG 26%, P< 0.05), elevating steady-state PmvO(2) (CON, MG: 10 +/- 2, WG: 9 +/- 1;beta-GPA, MG 16 +/- 2, WG 18 +/- 2 mmHg, P< 0.05). This reflected an increased (Q) over dotO(2)/(V) over dotO(2) ratio due primarily to a reduced (V) over dotO(2) in beta-CPA muscles. It is likely that this adaptation helps facilitate the beta-CPA-induced enhancement of contractile function in fast-twitch muscles. (C) 2012 Elsevier B.V. All rights reserved.
Scientific journal, English

Kinetics of muscle deoxygenation and microvascular PO2 during contractions in rat: comparison of optical spectroscopy and phosphorescence-quenching techniques
Shunsaku Koga; Yutaka Kano; Thomas J. Barstow; Leonardo F. Ferreira; Etsuko Ohmae; Mizuki Sudo; David C. Poole
Journal of Applied Physiology, AMER PHYSIOLOGICAL SOC, 112, 1, 26-32, Jan. 2012, Peer-reviwed, Koga S, Kano Y, Barstow TJ, Ferreira LF, Ohmae E, Sudo M, Poole DC. Kinetics of muscle deoxygenation and microvascular PO2 during contractions in rat: comparison of optical spectroscopy and phosphorescence-quenching techniques. J Appl Physiol 112: 26-32, 2012. First published October 6, 2011; doi:10.1152/japplphysiol.00925.2011.-The overarching presumption with near-infrared spectroscopy measurement of muscle deoxygenation is that the signal reflects predominantly the intramuscular microcirculatory compartment rather than intramyocyte myoglobin (Mb). To test this hypothesis, we compared the kinetics profile of muscle deoxygenation using visible light spectroscopy (suitable for the superficial fiber layers) with that for microvascular O-2 partial pressure (i.e., PmvO(2), phosphorescence quenching) within the same muscle region (0.5 similar to 1 mm depth) during transitions from rest to electrically stimulated contractions in the gastrocnemius of male Wistar rats (n = 14). Both responses could be modeled by a time delay (TD), followed by a close-to-exponential change to the new steady level. However, the TD for the muscle deoxygenation profile was significantly longer compared with that for the phosphorescencequenching PmvO(2) [8.6 +/- 1.4 and 2.7 +/- 0.6 s (means +/- SE) for the deoxygenation and PmvO(2), respectively; P < 0.05]. The time constants (tau) of the responses were not different (8.8 +/- 4.7 and 11.2 +/- 1.8 s for the deoxygenation and PmvO(2), respectively). These disparate (TD) responses suggest that the deoxygenation characteristics of Mb extend the TD, thereby increasing the duration (number of contractions) before the onset of muscle deoxygenation. However, this effect was insufficient to increase the mean response time. Somewhat differently, the muscle deoxygenation response measured using near-infrared spectroscopy in the deeper regions (similar to 5 mm depth) (similar to 50% type I Mb-rich, highly oxidative fibers) was slower (tau = 42.3 +/- 6.6 s; P < 0.05) than the corresponding value for superficial muscle measured using visible light spectroscopy or PmvO(2) and can be explained on the basis of known fiber-type differences in PmvO(2) kinetics. These data suggest that, within the superficial and also deeper muscle regions, the tau of the deoxygenation signal may represent a useful index of local O-2 extraction kinetics during exercise transients.
Scientific journal, English

Skeletal Muscle-Specific Expression of PGC-1 alpha-b, an Exercise-Responsive Isoform, Increases Exercise Capacity and Peak Oxygen Uptake
Miki Tadaishi; Shinji Miura; Yuko Kai; Yutaka Kano; Yuichi Oishi; Osamu Ezaki
PLOS ONE, PUBLIC LIBRARY SCIENCE, 6, 12, e28290, Dec. 2011, Peer-reviwed, Background: Maximal oxygen uptake (VO2max) predicts mortality and is associated with endurance performance. Trained subjects have a high VO2max due to a high cardiac output and high metabolic capacity of skeletal muscles. Peroxisome proliferator-activated receptor c coactivator 1 alpha (PGC-1 alpha), a nuclear receptor coactivator, promotes mitochondrial biogenesis, a fiber-type switch to oxidative fibers, and angiogenesis in skeletal muscle. Because exercise training increases PGC-1 alpha in skeletal muscle, PGC-1 alpha-mediated changes may contribute to the improvement of exercise capacity and VO2max. There are three isoforms of PGC-1 alpha mRNA. PGC-1 alpha-b protein, whose amino terminus is different from PGC-1 alpha-a protein, is a predominant PGC-1a isoform in response to exercise. We investigated whether alterations of skeletal muscle metabolism by overexpression of PGC-1 alpha-b in skeletal muscle, but not heart, would increase VO(2ma)x and exercise capacity.
Methodology/Principal Findings: Transgenic mice showed overexpression of PGC-1 alpha-b protein in skeletal muscle but not in heart. Overexpression of PGC-1 alpha-b promoted mitochondrial biogenesis 4-fold, increased the expression of fatty acid transporters, enhanced angiogenesis in skeletal muscle 1.4 to 2.7-fold, and promoted exercise capacity (expressed by maximum speed) by 35% and peak oxygen uptake by 20%. Across a broad range of either the absolute exercise intensity, or the same relative exercise intensities, lipid oxidation was always higher in the transgenic mice than wild-type littermates, suggesting that lipid is the predominant fuel source for exercise in the transgenic mice. However, muscle glycogen usage during exercise was absent in the transgenic mice.
Conclusions/Significance: Increased mitochondrial biogenesis, capillaries, and fatty acid transporters in skeletal muscles may contribute to improved exercise capacity via an increase in fatty acid utilization. Increases in PGC-1 alpha-b protein or function might be a useful strategy for sedentary subjects to perform exercise efficiently, which would lead to prevention of life-style related diseases and increased lifespan.
Scientific journal, English

Control of microvascular PO2 kinetics following onset of muscle contractions: role for AMPK
Yutaka Kano; David C. Poole; Mizuki Sudo; Toshiro Hirachi; Shinji Miura; Osamu Ezaki
Corresponding, American Journal of Physiology-Regulatory Integrative and Comparative Physiology, AMER PHYSIOLOGICAL SOC, 301, 5, R1350-R1357, Nov. 2011, Peer-reviwed, Kano Y, Poole DC, Sudo M, Hirachi T, Miura S, Ezaki O. Control of microvascular PO2 kinetics following onset of muscle contractions: role for AMPK. Am J Physiol Regul Integr Comp Physiol 301: R1350-R1357, 2011. First published August 17, 2011; doi:10.1152/ajpregu.00294.2011.-The microvascular partial pressure of oxygen (Pmv(O2)) kinetics following the onset of exercise reflects the relationship between muscle O-2 delivery and uptake ((V) over dotO(2)). Although AMP-activated protein kinase (AMPK) is known as a regulator of mitochondria and nitric oxide metabolism, it is unclear whether the dynamic balance of O-2 delivery and (V) over dotO(2) at exercise onset is dependent on AMPK activation level. We used transgenic mice with muscle-specific AMPK dominant-negative (AMPK-DN) to investigate a role for skeletal muscle AMPK on Pmv(O2) kinetics following onset of muscle contractions. Phosphorescence quenching techniques were used to measure Pmv(O2) at rest and across the transition to twitch (1 Hz) and tetanic (100 Hz, 3-5 V, 4-ms pulse duration, stimulus duration of 100 ms every 1 s for 1 min) contractions in gastrocnemius muscles (each group n = 6) of AMPK-DN mice and wild-type littermates (WT) under isoflurane anesthesia with 100% inspired O-2 to avoid hypoxemia. Baseline Pmv(O2) before contractions was not different between groups (P > 0.05). Both muscle contraction conditions exhibited a delay followed by an exponential decrease in Pmv(O2). However, compared with WT, AMPK-DN demonstrated 1) prolongation of the time delay before Pmv(O2) began to decline (1 Hz: WT, 3.2 +/- 0.5 s; AMPK-DN, 6.5 +/- 0.4 s; 100 Hz: WT, 4.4 +/- 1.0 s; AMPK-DN, 6.5 +/- 1.4 s; P < 0.05), 2) a faster response time (i.e., time constant; 1 Hz: WT, 19.4 +/- 3.9 s; AMPK-DN, 12.4 +/- 2.6 s; 100 Hz: WT, 15.1 +/- 2.2 s; AMPK-DN, 9.0 +/- 1.7 s; P < 0.05). These findings are consistent with the presence of substantial mitochondrial and microvascular dysfunction in AMPK-DN mice, which likely slows O-2 consumption kinetics (i.e., oxidative phosphorylation response) and impairs the hyperemic response at the onset of contractions thereby sowing the seeds for exercise intolerance.
Scientific journal, English

Adaptations of Myoglobin in Rat Skeletal Muscles to Endurance Running Training-Effects of Intersity, Duration, and Period of Training
曽野部 崇; 稲垣 薫克; 狩野 豊
Corresponding, J. Jap. Orthop. Assoc., 85, 7, 415-419, Jul. 2011, Peer-reviwed
Scientific journal, Japanese

Progressive arteriolar vasoconstriction and fatigue during tetanic contractions of rat skeletal muscle are inhibited by alpha-receptor blockade
Tadakatsu Inagaki; Takashi Sonobe; David C. Poole; Yutaka Kano
Corresponding, JOURNAL OF PHYSIOLOGICAL SCIENCES, SPRINGER TOKYO, 61, 3, 181-189, May 2011, Peer-reviwed, Voluntary muscle contractions activate sympathetic efferent pathways. Using a fatiguing electrical stimulation protocol designed specifically to enhance sympathetically-mediated vasoconstrictor tone, we explored the temporal profile and mechanistic bases of the evoked vasoconstrictor response and its role in muscle fatigue. Spinotrapezius muscles of Wistar rats were exteriorized and stimulated tetanically (100 Hz, 6-8 V, stimulus duration 700 ms) every 3 s for 2.5 min. The extent and time course of diameter changes in arterioles (1A and 2A) and venules (1V and 2V) were determined after each of 10 discrete sets of muscle stimulation at 5-min intervals. At first, to compare the effect of stimulation parameters in this preparation, stimulations were performed with rectangular pulses of either 0.2- or 4-ms pulse duration. As expected the 0.2-ms pulse stimulation did not affect arteriolar diameter or muscle fatigability. In contrast, during and following 4-ms pulse stimulations, there was a surprising arteriolar vasoconstriction rather than the expected vasodilation. Arteriolar (but not venular) vasoconstriction (reduced arteriolar diameter by 38.6 +/- 2.6% in the 10th set) increased progressively with muscle fatigue (to 29 +/- 12% of initial tension in the 10th set) for the 4-ms pulse condition. Superfusion with the selective alpha 1-adrenergic receptor antagonist prazosin (1 mu M) and/or alpha 2-adrenergic receptor antagonist rauwolscine (10 mu M) abolished both the arteriolar vasoconstriction and significantly reduced fatigue (i.e., % initial tension, alpha 1: 46.8 +/- 10.3%; alpha 2: 39.0 +/- 5.8%; alpha 1 + alpha 2: 48.7 +/- 16.3% in the 10th set; all P < 0.05 vs. control). We conclude that sequential bouts of contractions induce a progressively greater degree of alpha-adrenergic receptor-induced arteriolar (but not venular) vasoconstriction which contributes significantly to fatigue in this model.
Scientific journal, English

What is coefficient of speed endurance to achieve two-hour marathon?
Yutaka Kano; Hidetaka Okada; Yasunori Morioka
Corresponding, Journal of Applied Physiology, AMER PHYSIOLOGICAL SOC, 110, 1, 289-289, Jan. 2011, Peer-reviwed
Scientific journal, English

Sex differences in intracellular Ca2+ accumulation following eccentric contractions of rat skeletal muscle in vivo
Takashi Sonobe; Tadakatsu Inagaki; Mizuki Sudo; David C. Poole; Yutaka Kano
Corresponding, American Journal of Physiology-Regulatory Integrative and Comparative Physiology, AMER PHYSIOLOGICAL SOC, 299, 4, R1006-R1012, Oct. 2010, Peer-reviwed, Sonobe T, Inagaki T, Sudo M, Poole DC, Kano Y. Sex differences in intracellular Ca2+ accumulation following eccentric contractions of rat skeletal muscle in vivo. Am J Physiol Regul Integr Comp Physiol 299: R1006-R1012, 2010. First published July 14, 2010; doi:10.1152/ajpregu.00623.2009.-It is commonly believed that estrogen and sex influences play significant effects in skeletal muscle damage following eccentric exercise. The mechanistic bases for this sex-specific phenomenon remain to be resolved. The muscle damage has been linked to loss of Ca2+ homeostasis and resultant intramyocyte Ca2+ ([Ca2+](i)) accumulation; therefore, we tested the hypothesis that the greater eccentric exercise-induced muscle damage in males would be associated with more pronounced [Ca2+](i) accumulation. The intact spinotrapezius muscle of adult Wistar rats [male, female, and ovariectomized (OVX)-to investigate the effects of estrogen] was exteriorized. Tetanic eccentric contractions (100 Hz, 700-ms duration, 20 contractions/min for a total of 10 sets of 50 contractions) were elicited by electrical stimulation during synchronized muscle stretch of 10% resting muscle length. The fluorescence ratio (F340/F-380 nm) was determined from images captured following each set of contractions, and fura-2 AM was used to estimate [Ca2+](i) and changes thereof. Following eccentric contractions, [Ca2+](i) increased significantly in male (42.8 +/- 5.3%, P < 0.01) but not in female (9.4 +/- 3.5%) rats. OVX evidenced an intermediate response (17.0 +/- 1.2%) that remained significantly reduced compared with males. These results demonstrate that females maintain [Ca2+](i) homeostasis following novel eccentric contractions, whereas males do not, which is consistent with a role for elevated [Ca2+](i) in eccentric exercise-induced muscle damage. The presence of normal estrogen levels is not obligatory for the difference between the sexes.
Scientific journal, English

Myofiber apoptosis occurs in the inflammation and regeneration phase following eccentric contractions in rats
Mizuki Sudo; Yutaka Kano
Corresponding, Journal of Physiological Sciences, SPRINGER TOKYO, 59, 6, 405-412, Nov. 2009, Peer-reviwed, Eccentric contractions (ECC) induce myofibrillar collapse, edema, and inflammation in muscle cells. Although apoptosis of myonuclei following ECC is activated during the inflammatory phase, the apoptosis response of the regenerative phase remains to be elucidated. The aim of the present study was to determine the inflammatory and regenerative phase of the apoptosis responses induced by ECC. In anesthetized rats, the tibialis anterior muscles were subjected to ECC repeated 40 times, evoked by surface electric stimulation (100 Hz, 10 V) with mechanical muscle stretch. Apoptosis was examined in the control group and in groups 1, 3, 7, and 14 days after ECC (each group, n = 4-6). Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive myonuclei were assessed by further labeling with dystrophin staining and DAPI. The expression of proteins related to apoptosis (Bcl-2 and Bax) was examined by Western blot assay. At 1 and 3 days, focal edema and necrotic myofibers invaded by mononuclear phagocytes were present, whereas regenerated myofibers with central nuclei were detected at 7 and 14 days. The occurrence of TUNEL-positive myonuclei increased significantly at 7 (7.0 +/- 1.5%) and 14 days (5.6 +/- 0.6%) compared with control (0.9 +/- 0.5%). Further we found that myonuclear apoptosis was restricted to the subsarcolemmal space at 7 and 14 days and markedly absent from the central nucleus. The Bax/Bcl-2 ratio was significantly higher at 3 (4.5 +/- 0.9) and 7 days (3.4 +/- 0.5) after ECC. In conclusion, myofiber apoptotic responses following ECC are present not only in the inflammatory phase but also persist during the regenerative phase.
Scientific journal, English

Histological Skeletal Muscle Damage and Surface EMG Relationships Following Eccentric Contractions
Yutaka Kano; Kazumi Masuda; Hirotaka Furukawa; Mizuki Sudo; Kazuyuki Mito; Kazuyoshi Sakamoto
Corresponding, Journal of Physiological Sciences, PHYSIOLOGICAL SOC JAPAN, 58, 5, 349-355, Oct. 2008, Peer-reviwed, This study examined the effects of a different number of eccentric contractions (ECs) on histological characteristics, surface electromyogram (EMG) parameters (integral EMG, iEMG; muscle fiber conduction velocity, MFCV; and action potential waveform), and isometric peak torque using the rat EC model. Male Wistar rats (n = 40) were anesthetized, and ECs were initiated in the tibialis anterior muscle via electrical stimulation while the muscle was being stretched by electromotor. The rats were grouped according to the number of ECs (EC1, EC5, EC10, EC20, EC30, EC40, and EC100). Three days after the ECs, surface EMG signals and isometric peak torque were measured during evoked twitch contractions via electrical stimulation of the peroneal nerve. The muscle damage was evaluated from hematoxylin-eosin (HE) stained cross sections as a relative number of damaged fibers to intact fibers. Intense histological muscle damage (approximately 50% to 70% of the fiber), loss of isometric peak torque, disturbance of action potential waveform, and depression of iEMG (approximately -60% to -70%) were observed at EC20, EC30, EC40, and EC100. On the other hand, the MFCV did not change in any EC group. Although muscle damage and pathological surface EMG signals were not found at EC10, isometric peak torque was reduced significantly. In conclusion, the extent of histological muscle damage is not proportionally related to the number of ECs. Muscle damage was reflected by iEMG and action potential waveforms, but not by MFCV, which remained unaffected even though approximately 50% to 70% of the fiber demonstrated injury.
Scientific journal, English

Intracellular calcium accumulation following eccentric contractions in rat skeletal muscle in vivo: role of stretch-activated channels
Takashi Sonobe; Tadakatsu Inagaki; David C. Poole; Yutaka Kano
Corresponding, American Journal of Physiology-Regulatory Integrative and Comparative Physiology, AMER PHYSIOLOGICAL SOC, 294, 4, R1329-R1337, Apr. 2008, Peer-reviwed, Although the accumulation of intracellular calcium ions ([Ca2+](i)) is associated with muscle damage, little is known regarding the temporal profile of muscle [Ca2+](i) under in vivo conditions, and, specifically, the effects of different contraction types [e. g., isometric (ISO); eccentric (ECC)] on [Ca2+](i) remain to be determined. The following hypotheses were tested. 1) For 90 min at rest, an in vivo vs. in vitro preparation would better maintain initial [Ca2+](i). 2) Compared with ISO, ECC contractions (50 contractions, 10 sets, 5-min interval) would lead to a greater increase of [Ca2+](i). 3) Elevated [Ca2+](i) during ECC would be reduced or prevented by the stretch-activated ion channel blockers streptomycin and gadolinium (Gd3+). Spinotrapezius muscles of Wistar rats were exteriorized (in vivo) or excised (in vitro). [Ca2+](i) was evaluated by loading the muscle with fura 2-AM using fluorescence imaging. [Ca2+](i) rose progressively beyond 40 min at rest under in vitro but not in vivo conditions during the 90-min protocol. In vivo [Ca2+](i) increased more rapidly during ECC (first set) than ISO (fifth set) (P < 0.05 vs. precontraction values). The peak level of [Ca2+](i) was increased by 21.5% (ISO) and 42.8% (ECC) after 10 sets (both P < 0.01). Streptomycin and Gd3+ abolished the majority of [Ca2+](i) increase during ECC (69 and 86% reduction, respectively; P < 0.01 from peak [Ca2+](i) of ECC). In conclusion, in vivo quantitative analyses demonstrated that ECC contractions elevate [Ca2+](i) significantly more than ISO contractions and that stretch-activated channels may play a permissive role in this response.
Scientific journal, English

Proanthocyanidin promotes free radical-scavenging activity in muscle tissues and plasma
Kazumi Masuda; Tatsuya Hori; Kai Tanabe; Yutaka Kano; Aki Hirayama; Sohji Nagase
Applied Physiology Nutrition and Metabolism, NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS, 32, 6, 1097-1104, Dec. 2007, Peer-reviwed, The present study was carried out to clarify the effect of oral administration of proanthocyanidin (PA) on radical-scavenging activity in muscle and plasma using electron spin resonance (ESR). Eight-week-old male Wistar rats were orally administered with 3 doses per day of 1 mL of 0.05% (PA0.05), 0.5% (PA0.5) or 5% (PA5) PA for 1 week. Control animals received the same volume of distilled water. We also examined the effect of a single dose of 0.5% PA. Blood and muscle were collected from rats 1 h after the final administration. Scavenging activity against superoxide anions in the plasma and m. soleus (Sol), m. plantaris (Pla), deep and surface areas of the m. gastrocnemius (GasD and GasS, respectively) and myocardium (Hrt) was determined using ESR with the spin trap, 5,5-dimethyl-1-pyrroline-N-oxide The scavenging activity in plasma for all groups given PA was 34%-44% higher than the control (p < 0.05). The scavenging activity in Hrt, Sol and GasD increased by up to 50% compared with the control and tended to increase depending on the dose of PA (p < 0.05). The impact of a single dose of PA was undetectable in all tissues. These results suggested that 1 week of oral PA improves the radical-scavenging activity in both plasma and muscle, especially in highly oxidative muscle. A single dose of PA was insufficient to improve the antioxidative capacity of muscle tissues.
Scientific journal, English

Effects of Type II diabetes on muscle microvascular oxygen pressures
Danielle J. Padilla; Paul McDonough; Brad J. Behnke; Yutaka Kano; K. Sue Hageman; Timothy I. Musch; David C. Poole
Respiratory Physiology & Neurobiology, ELSEVIER SCIENCE BV, 156, 2, 187-195, May 2007, Peer-reviwed, We tested the hypothesis that muscle microvascular O-2 pressure (P-mvO2; reflecting the O-2 delivery (Q(O2)) to O-2 uptake (V-O2) ratio) would be lowered in the spinotrapezius muscle of Goto-Kakizaki (GK) Type II diabetic rats (n = 7) at rest and during twitch contractions when compared to control (CON; n = 5) rats. At rest, P-mvO2 was lower in GK versus CON rats (CON: 29 +/- 2; GK: 18 +/- 2 Torr; P < 0.05). At the onset of contractions, GK rats evidenced a faster change in P-mvO2 than CON (i.e., time constant (tau); CON: 16 +/- 4; GK: 6 +/- 12 s; P < 0.05). In contrast to the monoexponential fall in P-mvO2 to the steady-state level seen in CON, GK rats exhibited a biphasic P-mvO2 response that included a blunted (or non-existent) P-mvO2, decrease followed by recovery to a steady-state P-mvO2 that was at, or slightly above, resting values. Compared with CON, this decreased P-mvO2 across the transition to a higher metabolic rate in Type II diabetes would be expected to impair blood-muscle 02 exchange and contractile function. (c) 2006 Elsevier B.V All rights reserved.
Scientific journal, English

Effects of Type II diabetes on capillary hemodynamics in skeletal muscle
Danielle J. Padilla; Paul McDonough; Brad J. Behnke; Yutaka Kano; K. Sue Hageman; Timothy I. Musch; David C. Poole
American Journal of Physiology - Heart and Circulatory Physiology, AMER PHYSIOLOGICAL SOC, 291, 5, H2439-H2444, 2006, Peer-reviwed, Microcirculatory red blood cell (RBC) hemodynamics are impaired within skeletal muscle of Type I diabetic rats (Kindig CA, Sexton WL, Fedde MR, and Poole DC. Respir Physiol 111: 163-175, 1998). Whether muscle microcirculatory dysfunction occurs in Type II diabetes, the more prevalent form of the disease, is unknown. We hypothesized that Type II diabetes would reduce the proportion of capillaries supporting continuous RBC flow and RBC hemodynamics within the spinotrapezius muscle of the Goto-Kakizaki Type II diabetic rat (GK). With the use of intravital microscopy, muscle capillary diameter (dc), capillary lineal density, capillary tube hematocrit (Hctcap), RBC flux (FRBC), and velocity (VRBC) were measured in healthy male Wistar (control: n = 5, blood glucose, 105 ± 5 mg/dl) and male GK (n = 7, blood glucose, 263 ± 34 mg/dl) rats under resting conditions. Mean arterial pressure did not differ between groups (P >
0.05). Sarcomere length was set to a physiological length (∼2.7 μm) to ensure that muscle stretching did not alter capillary hemodynamics
dc was not different between control and GK rats (P >
0.05), but the percentage of RBC-perfused capillaries (control: 93 ± 3
GK: 66 ± 5 %), Hctcap, VRBC, FRBC, and O 2 delivery per unit of muscle were all decreased in GK rats (P <
0.05). This study indicates that Type II diabetes reduces both convective O 2 delivery and diffusive O2 transport properties within muscle microcirculation. If these microcirculatory deficits are present during exercise, it may provide a basis for the reduced O2 exchange characteristic of Type II diabetic patients. Copyright © 2006 the American Physiological Society.
Scientific journal, English

Effects of eccentric exercise on microcirculation and microvascular oxygen pressures in rat spinotrapezius muscle
Y Kano; DJ Padilla; BJ Behnke; KS Hageman; TI Musch; DC Poole
Lead, Journal of Applied Physiology, AMER PHYSIOLOGICAL SOC, 99, 4, 1516-1522, Oct. 2005, Peer-reviwed, A single bout of eccentric exercise results in muscle damage, but it is not known whether this is correlated with microcirculatory dysfunction. We tested the following hypotheses in the spinotrapezius muscle of rats either 1 (DH-1; n = 6) or 3 (DH-3; n = 6) days after a downhill run to exhaustion (90-120 min; - 14 degrees grade): 1) in resting muscle, capillary hemodynamics would be impaired, and 2) at the onset of subsequent acute concentric contractions, the decrease of microvascular O-2 pressure (Pmv(O2)), which reflects the dynamic balance between O-2 delivery and O-2 utilization, would be accelerated compared with control (Con, n = 6) rats. In contrast to Con muscles, intravital microscopy observations revealed the presence of sarcomere disruptions in DH-1 and DH-3 and increased capillary diameter in DH-3 (Con: 5.2 +/- 0.1; DH-1: 5.1 +/- 0.1; DH-3: 5.6 +/- 0.1 mu m; both P < 0.05 vs. DH-3). At rest, there was a significant reduction in the percentage of capillaries that sustained continuous red blood cell (RBC) flux in both DH running groups (Con: 90.0 +/- 2.1; DH-1: 66.4 +/- 5.2; DH-3: 72.9 +/- 4.1%, both P < 0.05 vs. Con). Capillary tube hematocrit was elevated in DH-1 but reduced in DH-3 (Con: 22 +/- 2; DH-1: 28 +/- 1; DH-3: 16 +/- 1%; all P < 0.05). Although capillary RBC flux did not differ between groups (P > 0.05), RBC velocity was lower in DH-1 compared with Con (Con: 324 +/- 43; DH-1: 212 +/- 30; DH-3: 266 +/- 45 mu m/s; P < 0.05 DH-1 vs. Con). Baseline Pmv(O2), before contractions was not different between groups (P > 0.05), but the time constant of the exponential fall to contracting Pmv(O2) values was accelerated in the DH running groups (Con: 14.7 +/- 1.4; DH-1: 8.9 +/- 1.4; DH-3: 8.7 +/- 1.4 s, both P < 0.05 vs. Con). These findings are consistent with the presence of substantial microvascular dysfunction after downhill eccentric running, which slows the exercise hyperemic response at the onset of contractions and reduces the Pmv(O2) available to drive blood-muscle O-2 delivery.
Scientific journal, English

Downhill running a model of exercise hyperemia in the rat spinotrapezius muscle
Y Kano; D Padilla; KS Hageman; DC Poole; TI Musch
Lead, Journal of Applied Physiology, AMER PHYSIOLOGICAL SOC, 97, 3, 1138-1142, Sep. 2004, Peer-reviwed, To utilize the rat spinotrapezius muscle as a model to investigate the microcirculatory consequences of exercise training, it is necessary to design an exercise protocol that recruits this muscle. There is evidence that the spinotrapezius is derecruited during standard treadmill exercise protocols performed on the uphill treadmill (i.e., 6degrees incline). This investigation tested the hypothesis that downhill running would effectively recruit the spinotrapezius muscle as assessed by the presence of an exercise hyperemia response. We used radioactive 15-mum microspheres to determine blood flows in the spinotrapezius and selected hindlimb muscles of female Sprague-Dawley rats at rest and during downhill (i.e., - 14degrees incline; 331 +/- 5 g body wt, n = 7) and level ( i.e., 0degrees incline; 320 +/- 11 g body wt, n = 5) running at 30 m/min. Both level and downhill exercise increased blood flow to all hindlimb muscles ( P < 0.01). However, in marked contrast to the absence of a hyperemic response to level running, blood flow to the spinotrapezius muscle increased from 26 +/- 6 ml &BULL; min(-1) &BULL; 100 g(-1) at rest to 69 +/- 8 ml &BULL; min(-1) &BULL; 100 g(-1) during downhill running ( P < 0.01). These findings indicate that downhill running represents an exercise paradigm that recruits the spinotrapezius muscle and thereby constitutes a tenable physiological model for investigating the adaptations induced by exercise training (i.e., the mechanisms of altered microcirculatory control by transmission light microscopy).
Scientific journal, English

Time course of capillary structure changes in rat skeletal muscle following strenuous eccentric exercise
Y Kano; K Sampei; H Matsudo
Lead, Acta Physiologica Scandinavica, BLACKWELL PUBLISHING LTD, 180, 3, 291-299, Mar. 2004, Peer-reviwed, Aim: We examined the time course of capillary structure changes in rat skeletal muscle at 1, 3 and 7 days after strenuous eccentric exercise.
Methods: The right gastrocnemius muscles of anaesthetized male Wistar rats were subjected to 300 controlled eccentric contractions using electrical stimulation. The contralateral gastrocnemius muscle was used as control. All morphometric parameters were determined in in situ perfused gastrocnemius muscles in red (Gr, predominantly slow-twitch fibre) and white (Gw, predominantly fast-twitch fibre) portions.
Results: Muscle fibre damage was evident on days 1, 3 and 7 in Gr (29.3-53.9% damaged fibres) and Gw (58.9-86.8% damaged fibres) of exercised legs. Electron micrographs of transverse sections did not display collapsed or obstructed capillaries in exercised legs, and capillary endothelial cells retained their normal structures. However, capillary luminal shapes and area were altered in exercised legs on days 1 and 3. The ratio between minimal and maximal capillary diameter in a transverse section (i.e. luminal ellipticity) significantly differed when comparing control (Gr, 0.75 +/- 0.02; Gw, 0.79 +/- 0.03) and exercised legs (Gr, 0.65 +/- 0.03; Gw, 0.66 +/- 0.04) at 1 day after exercise. The mean capillary luminal area was significantly increased in exercised legs after 1 day (Gw, +24.3%) and 3 days (Gr, +31.9%; Gw, +62.2%) compared with control.
Conclusion: We conclude that (1) capillary endothelial cell structure was maintained in damaged muscles, (2) changes in capillary lumen shapes and distensibility occur in the degenerated muscle up to 3 days after the eccentric contraction period.
Scientific journal, English

Effects of aging on capillary number and luminal size in rat soleus and plantaris muscles
Y Kano; S Shimegi; H Furukawa; H Matsudo; T Mizuta
Lead, Journals of Gerontology Series A-Biological Sciences and Medical Sciences, GERONTOLOGICAL SOCIETY AMER, 57, 12, B422-B427, Dec. 2002, Peer-reviwed, To clarify aging-related changes in the capillary network in skeletal muscle, we morphometrically examined the capillary supply to individual muscle fibers and capillary luminal size in young (3-month-old) and old (19-month-old) male Wistar rats. All morphometric parameters for capillary and muscle fiber were determined in the cross sections of the perfusion-fixed soleus (SOL) and plantaris (PL) muscles. The range of fiber size was larger in the old muscles because of hypertrophy and atrophy of fibers. However, the capillary supply to individual muscle fibers, assessed as the mean of capillary contacts around a muscle fiber, did not change with aging in SOL muscle (young rats = 7.8 +/- 0.4 vs old rats = 8.1 +/- 0.8) or PL muscle (young rats = 6.4 +/- 0.3 vs old rats = 7.0 +/- 0.9). The ratio of individual muscle fiber area to the number of capillary contacts around a muscle fiber did not differ between young rats (SOL = 361.7 +/- 76.0; PL = 264.7 +/- 20.9) and old rats (SOL = 350.2 +/- 61.3; PL = 296.8 +/- 44.9). The mean capillary luminal diameter did not differ statistically in young and old rats (SOL, young rats = 5.3 +/- 0.5 vs old rats = 5.1 +/- 0.1; PL, young rats = 5.0 +/- 0.3 vs old rats = 5.4 +/- 0.2). In conclusion, the relationship between capillary supply and muscle fiber size is similar for both young and old rats, and the luminal size of each capillary was maintained with advancing age.
Scientific journal, English

A case study on the progress of female sprint performance
Kyoko Inaba; Ken-ichi Katoh; Masashi Miyamaru; Shinya Kuno; Mitsugi Ogata; Yutaka Kano
Taiikugaku kenkyu (Japan Journal of Physical Education, Health and Sport Sciences), Japan Society of Physical Education, Health, and Sport Sciences, 47, 5, 463-472, 2002, Peer-reviwed
Scientific journal, Japanese

Changes in capillary luminal diameter in rat soleus muscle after hind-limb suspension
Y Kano; S Shimegi; H Takahashi; K Masuda; S Katsuta
Lead, Acta Physiologica Scandinavica, WILEY, 169, 4, 271-276, Aug. 2000, Peer-reviwed, This study examined the rime course change of the capillary luminal diameter and the number of capillaries in the rat soleus muscle during hind-limb suspension. Male Wistar rats were divided into 1 and 3 weeks of hind-limb suspension (HS) groups (HS-1 and HS-3). The HS groups were compared with age-matched control groups. All morphometric parameters with respect to capillary and muscle fibre cross-sectional area were determined in perfusion-fixed soleus muscles. After 1 and 3 weeks of hind-limb suspension, the mean muscle fibre cross-sectional area was significantly decreased in HS-1 (-32.0%) and HS-3 (-59.3%) compared with age-matched control groups. Despite a lower capillary-to-fibre ratio (HS-1,-19.3%; HS-3, -21.2%), the capillary density was unchanged in HS-1 and significantly increased in HS-3 compared with age-matched control groups. The mean capillary luminal diameter was significantly smaller in HS-1 (-19.9%) and HS-3 (-21.9%) than in the age-matched control groups. The capillary-to-fibre perimeter ratio which indicates the capillary surface area available for gas exchange between blood and tissue did not significantly differ between control groups and HS groups, in conclusion, the morphometrical adaptations in rat soleus with the suspension involved changes in both the capillary luminal diameter and number of capillaries, and the change in capillary surface area was proportional to the degree of muscle atrophy in HS groups.
Scientific journal, English

Relationship between hip strength and sprint running performance in sprinters
渡辺信晃; 榎本好孝; 大山卞圭吾; 狩野豊; 安井年文; 宮下憲; 久野譜也; 勝田茂
Japan Journal of Physical Education, Japan Society of Physical Education, Health and Sport Sciences, 45, 4, 520-529, Jul. 2000, Peer-reviwed, The purposes of this study were 1)to investigate the relationship between sprint running performance and isokinetic hip strength, and 2)to clarify the muscles that are important in sprinting from the standpoint of isokinetic strength and muscle cross-sectional area(CSA).Sixteen male(100m sprinting time 10.99±0.46s)and 12 female(12.50±0.44s)subjects ran 60m and their sprinting speed was measured from 30 to 60m.Isokinetic strength of hip and knee flexion and extension(Nm)were mesured at 60, 180 and 300 deg/s.Magnetic resonance imaging(MRI)was used to determine the muscle cross-sectional area of the thigh(upper, middle and lower femur)and trunk.In females, there were no significant correlations between sprinting speed and isokinetic strength.In males, there were significant correlations between sprinting speed and hip strength(absolute value)at all angular velocities(r=0.51-0.75, p<0.05-0.01), except for hip extension at 300 deg/s.Extension at 60 deg/s was significant(r=0.64, p<0.01)only in the male knee.In males, there were significant correlations between the peak torque of hip extension and muscle CSAs of the hamstring and adductor(r=0.50-0.63, p<0.05-0.01), as well as between the peak torque of hip flexion and muscle CSAs of the psoas major and adductor(r=0.59-0.83, p<0.05-0.001).These results suggest that sprint running performance in males is influenced by the strength of hip flexion and extension.In addition, the muscle volume of the hamstring, adductor and psoas major muscles appears to play an important roles during sprint running in males.
Scientific journal, Japanese

スプリンターの筋横断面積と疾走速度との関係における性差
渡辺信晃; 榎本好孝; 狩野豊; 安井年文; 宮下憲; 久野譜也; 勝田茂
陸上競技研究, 日本学生陸上競技連合, 39, 39, 12-19, Dec. 1999, Peer-reviwed
Scientific journal, Japanese

Effect of age on rat aortic responses to acetylcholine and nitric oxide donor (NOC-18)
Y Kano; T Tanabe; J Nagasawa; T Mizuta
Corresponding, Research Communications in Molecular Pathology and Pharmacology, P J D PUBLICATIONS LTD, 105, 1-2, 173-176, 1999, Peer-reviwed, The purpose of the present study was to examine the effects of age on vascular responses to acetylcholine (ACh) and NO-releasing compound (NOC-18). The studies were performed in young (4 mo old, n = 8) and old (22 mo old, n = 6) male rats. Responses to ACh and NOC-18 were examined in vitro by using isolated abdominal aortic rings. The maximum relaxation response to ACh, an endothelium-dependent vasodilation, was lower in aortas from old rats. Sensitivity (mean effective concentration; EC50) of ACh in old rats was significantly less than in young rats. There were no differences in maximum NOC-18-induced relaxation, an endothelium-independent vasodilation, in aortas from young and old rats. On the other hand, the concentration-response curve for NOC-18 was shifted to the right and the sensitivity (EC50 to NOC-18) was lower in old rats. These results indicated that both endothelium-dependent vasodilation induced by ACh and endothelium-independent vasodilation induced by NOC-18 are impaired in aorta from old rats.
Scientific journal, English

Adaptations of myoglobin in rat skeletal muscles to endurance running training - Effects of intensity, duration and period of training
K Masuda; Y Kano; H Nakano; M Inaki; S Katsuta
JAPANESE JOURNAL OF PHYSICAL FITNESS AND SPORTS MEDICINE, JAPANESE SOC PHYSICAL FITNESS SPORTS MEDICINE, 47, 5, 561-571, Oct. 1998, Peer-reviwed, A study was conducted to clarify the effects of running intensity and duration of endurance training on myoglobin concentration ([Mb]) in rat skeletal muscles, and to clarify its temporal changes during the training. One hundred five male Wistar rats were divided into a training group and an untrained group. The training was carried out at 5 times a week for 12 weeks when the animals were 4 to 16 weeks of age. The training intensities were set at 20, 30 and 40 m/min with a duration of 60 min. The training duration was varied to 30, 60, 90 and 120 min when the rats were trained at 30 m/min. The temporal changes in the [Mb] were examined after the first, third and ninth week of training, during which the rats were trained at 40 m/min for 60 min per session. Three muscles (soleus:Sol, plantaris:PI, gastrocnemius-surface/deep : Gas-S, Gas-D) were analyzed for the [Mb] and citrate synthase activity (CS activity). With regard to the intensity of training, the [Mb] increased with exercise intensity in Sol, Gas-D and PI, but not in Gas-S. P1 showed a greater increase of the [Mb] than Sol or Gas-D. On the other hand, CS activity in red muscle (Sol and Gas-D) increased even at low intensity, whereas white muscle (fast-twitch muscle:P1 and Gas-S) showed a significant increase in CS activity at an intensity of 40 m/min. As to the duration of training, the [Mb] increased with the duration of running at 30 m/min of intensity, and showed the maximal adaptation with 90-min duration in all muscles except for Gas-S. Changes in CS activity according to the duration of running were similar to those for the [Mb] in all muscles. Finally, the [Mb] increased significantly with prolongation of the training period (after the 1 st, 3 rd and 9 th weeks training) in all muscles except Gas-S. However, the adaptive response of Mb tended to be delayed as compared with CS activity. These results suggest that 2) the response of Mb to training stimuli can depend on the muscle specificity (fiber type composition or the initial [Mb]), and level of motor unit recruitment in usual, 2) Mb synthesis can be enhanced by an increase of training intensity, 3) a training duration of 90 min can bring out the Mb adaptation maximally and 4) the adaptive response of Mb would need more time as compared with CS activity.
Scientific journal, Japanese

Characteristics of muscle oxygenation in elderly men determined by near infrared spectroscopy
T Shiozaki; Y Kano; S Watanabe; R Ajisaka; M Ishizu; S Katsuta; M Okada; S Kuno
JAPANESE JOURNAL OF PHYSICAL FITNESS AND SPORTS MEDICINE, JAPANESE SOC PHYSICAL FITNESS SPORTS MEDICINE, 47, 4, 393-400, Aug. 1998, Peer-reviwed, We used near-infrared spectroscopy (NIRS) to study noninvasively the effects of aging on changes in muscle oxygenation during steady bicycle exercise. For the study, 6 healthy young males and 13 healthy elderly male volunteers were recruited. To evaluate the physical fitness level and to determine exercise intensity, the ventilatory threshold (VT) was first measured. As a result, elderly subjects were divided into two groups according to O-2 uptake at VT (Elderly-H; 936.0 +/- 26.4, Elderly-L; 695.3 +/- 29.9, Young; 790.0 +/- 51.19 ml). Secondly we measured muscle oxygenation by NIRS at rest and during exercise at relative work intensities of VT; 20%, 40%, 60%, 80% and 100%. In all cases muscle oxygenation at rest and during exercise was expressed as a relative value from 100% oxygenation (oxygen capacity) established by thigh occlusion (ischemia). All subjects showed progressive deoxygenation with increasing intensity. There were no differences between the three groups in muscle oxygenation during exercise at relative work intensity of VT. These data suggest that aging and physical fitness level have no effect on muscle oxygenation below relative work intensity of VT.
Scientific journal, Japanese

Relationship between the morphorogical features adductor muscles and sprinting performance in sprinters
狩野豊; 高橋英幸; 森丘保典; 秋間広; 宮下憲; 久野譜也; 勝田茂
Lead, Japan Journal of Physical Education, Japan Society of Physical Education, Health and Sport Sciences, 41, 5, 352-359, Sep. 1997, Peer-reviwed, The relationship between the thigh muscle composition and the sprinting performance was investigated in 11 male adult sprinters (age/20.8±0.9 yrs, 100 m sprint time/11.20±0.33 sec). Axial images of the thigh muscle were taken by magnetic resonance imaging (MRI) at upper (70%) and middle (50%) position in femur. From these images, cross-sectional areas (CSA) of the quadriceps femoris, the hamstring and the adductor muscles were measured. The results of the regression analysis showed significant correlations between 100 m sprint time and both CSA of adductor and hamstring muscles at 70% position (r=-0.72 and r=-0.67, respectively). There were no significant correlations between 100 m sprint time and CSA of adductor or hamstring muscles at 50% position, and neither quadriceps femoris mudcles at 70 nor 50% positions. These results suggest that greater muscle volume of hamstring and adductor at upper position affect sprinting performance.
Scientific journal, Japanese

Adaptation of myoglobin in compensatory hypertrophied rat muscle
K Masuda; Y Kano; S Katsuta
Acta Physiologica Scandinavica, BLACKWELL SCIENCE LTD, 160, 4, 327-331, Aug. 1997, Peer-reviwed, This study investigated the time course change of myoglobin concentration ([Mb]) in skeletal muscle during muscle hypertrophy in rats. Seven groups of Wistar rats (n = 7 per group) were examined. Compensatory hypertrophy of the plantaris muscle was induced by the bilateral ablation of the medial and lateral heads of the gastrocnemius muscle, and the effect of compensatory hypertrophy on the [Mb] of the plantaris muscle was examined at 7, 21 and 42 days post-ablation. The [Mb] expressed as mg g(-1) wet muscle weight tended to decline at 7 days post-ablation (-12.1%) and returned to the control level by 42 days post-ablation, as did the muscle protein concentration. However, the [Mb] expressed as mg g(-1) protein weight was not significantly different between the ablation and control groups throughout the experimental period. The estimated Value of absolute Mb content in the whole plantaris muscle was significantly increased by 28.4% (P < 0.01) at 42 days post-ablation compared with the age-matched controls. Therefore, the longer period of compensatory activity allowed the Mb to increase in its absolute content, although the [Mb] did not exceed the level of control muscle. The capacity of facilitated oxygen diffusion and oxygen storage by Mb in the muscle cells will not change even when muscle enlargement takes place.
Scientific journal, English

Effects of different intensity endurance training on the capillary network in rat skeletal muscle
Y Kano; S Shimegi; K Masuda; H Sakato; H Ohmori; S Katsuta
Lead, International Journal of Microcirculation-Clinical and Experimental, KARGER, 17, 2, 93-96, Mar. 1997, Peer-reviwed, Effects of low- and high-intensity endurance training on the capillary luminal diameter and number were studied morphometrically in the rat plantaris muscle. Male Wistar-Imamichi rats were divided into three groups: sedentary control group (Cent, n = 9), low-intensity (running speed of 20 m/min) training group (T-20, n = 8) and high-intensity (running speed of 40 m/min) training group (T-40), n = 7). Rats in both training groups were subjected to each treadmill running program for 60 min/day, 5 days/week for 9 weeks. After 9 weeks of training, citrate synthase activity significantly increased in T-40 compared with Cent, but did not change in T-20. All morphometric parameters with respect to capillary and muscle fiber area were determined in the perfusion-fixed plantaris muscle. The mean muscle fiber areas in both T-20 and T-40 were similar to that in Cent. The capillary-to-fiber ratios were significantly higher in T-20 (2.28 +/- 0.06) and T-40 (2.29 +/- 0.06) than in Cent (2.00 +/- 0.07). The number of capillaries with a small luminal diameter (2-4 mu m) was significantly higher in T-20 than in Cent. In contrast, T-40 had a significantly higher number of capillaries with a large luminal diameter (8-10 mu m) compared with Cent. This study indicates that endurance training induces changes in the capillary luminal diameter as well as capillary number, and that the adaptive response of the capillary luminal diameter to endurance training depends on the training intensity.
Scientific journal, English

Morphological adaptation of capillary network in compensatory hypertrophied rat plantaris muscle
Yutaka Kano; Satoshi Shimegi; Kazumi Masuda; Hajime Ohmori; Shigeru Katsuta
Lead, European Journal of Applied Physiology and Occupational Physiology, 75, 2, 97-101, Feb. 1997, Peer-reviwed, The aim of this study was to examine the morphological adaptation of the capillary network in hypertrophied plantaris muscles by examining both capillary numbers and luminal circumferences. Hypertrophy of the plantaris muscle was induced by myectomy of the gastrocnemius muscle. This hypertrophy was characterised by increases in muscle mass and fibre cross-sectional area. All capillary parameters were determined using morphometric methods in perfusion-fixed plantaris muscle. Increased capillary-to-fibre ratio was observed in the overloaded plantaris muscle while no change was observed in the capillary luminal circumference. No differences were observed in the capillary density and the capillary-to-fibre perimeter ratio of the normal and the hypertrophied plantaris muscle. These results indicated that chronic overload-induced neocapillarization, but not enlargement of capillary luminal circumference, contributed to the prevention of decreases in the capillary-to-fibre perimeter ratio in the plantaris muscle in the hypertrophied process.
Scientific journal, English

異なる強度の持久性トレーニングがもたらす心室壁の毛細血管における形態変化
狩野豊; 増田和美; 七五三木聡; 坂戸英樹; 大森肇; 勝田茂
Lead, 体力科学, Jul. 1996, Peer-reviwed
Scientific journal, Japanese

Effects of endurance training on the morophology of the cardiac myocyte and capillary in the rat
狩野豊; 斉藤基一郎; 大野良樹; 勝田茂
Lead, Japan Journal of Physical Education, 39, 3, 225-233, May 1994, Peer-reviwed
Scientific journal, Japanese

In vivo環境下におけるマウス骨格筋ミトコンドリア内Ca²⁺動態の可視化—In vivo visualization of mitochondrial Ca²⁺ dynamics in mouse skeletal muscle during contractions
田中 嘉法; 田渕 絢香; 白川 英樹; 狩野 豊
東京 : 北隆館, Jan. 2024, アグリバイオ = Agricultural biotechnology, 8, 1, 60-64, Japanese, 2432-5511, AA12770259

High-speed 3D color planar lightwave circuit digital holographic microscope towards the observation of mammalian cells
Ayaka Tabuchi; Kenta Hayashi; Maryam Faheem; Yutaka Kano; Eriko Watanabe
SPIE, 20 Sep. 2023, Biomedical Imaging and Sensing Conference, 34-34, Peer-reviwed

In vivo環境下におけるマウス骨格筋ミトコンドリア内Ca²⁺動態の可視化—In vivo visualization of mitochondrial Ca²⁺ dynamics in mouse skeletal muscle during contractions
田中 嘉法; 田渕 絢香; 白川 英樹; 狩野 豊
東京 : ニューサイエンス社, Apr. 2023, 細胞, 55, 5, 335-338, Japanese, 1346-7557, AA11382662

Pharmacological inhibition of ryanodine receptors immediately after eccentric contractions exercise effectively reduces exercise-induced muscle damage in rat skeletal muscle
Ayaka Tabuchi; Yoshinori Tanaka; Ryo Takagi; David Poole; Yutaka Kano
Lippincott williams & wilkins, Sep. 2022, Medicine & science in sports & exercise, 54, 9, 615-615, English, Summary international conference, 0195-9131, 1530-0315, WOS:000888056602553

血流制限下の低強度電気刺激はラットの骨格筋におけるMCT発現を増強する
中島 敏明; 安田 智洋; 小尾 正太郎; 豊田 茂; 井上 晃男; 狩野 豊
日本臨床生理学会, Oct. 2018, 日本臨床生理学会雑誌, 48, 4, 106-106, Japanese, 0286-7052, 2019062743

筋収縮を支えるエネルギープラント;ミトコンドリアのNew Insights ミトコンドリアによる筋細胞内カルシウムイオンの調節
狩野 豊; 江島 弘晃
(一社)日本体力医学会, Feb. 2018, 体力科学, 67, 1, 14-14, Japanese, 0039-906X, 1881-4751, 2018245866, 201802229278437222, 130006315705

運動負荷・呼吸循環動態 ラット加圧モデルによる骨格筋各種蛋白質発現に及ぼす増強効果についての検討
中島 敏明; 安田 智洋; 小尾 正太郎; 豊田 茂; 井上 晃男; 狩野 豊
日本臨床生理学会, Oct. 2017, 日本臨床生理学会雑誌, 47, 4, 100-100, Japanese, 0286-7052, 2018070016

ラット加圧モデルによる骨格筋各種蛋白質発現に及ぼす増強効果について
中島 敏明; 安田 智洋; 小尾 正太郎; 豊田 茂; 井上 晃男; 狩野 豊
(NPO)日本臨床運動療法学会, Sep. 2017, 日本臨床運動療法学会雑誌, 19, 1, 75-75, Japanese, 2018016035

筋細胞内Ca2+調節におけるミトコンドリアの役割 PGC-1αマウスによる検証
江島 弘晃; 三浦 進司; 狩野 豊
(一社)日本体力医学会, Dec. 2015, 体力科学, 64, 6, 567-567, Japanese, 0039-906X, 1881-4751, 2016135895, 201602212588198191

血流制限下の電気刺激によるトレーニングのラット骨格筋各種蛋白質発現に及ぼす効果
中島 敏明; 安田 智洋; 小尾 正太郎; 井上 晃男; 狩野 豊
日本臨床生理学会, Oct. 2015, 日本臨床生理学会雑誌, 45, 4, 75-75, Japanese, 0286-7052, 2016116306

I型糖尿病がラット脊柱僧帽筋の形態および代謝的特性に及ぼす影響
脇坂 馬里雄; 田中 嘉法; 江島 弘晃; 狩野 豊
(一社)日本体力医学会, Dec. 2014, 体力科学, 63, 6, 559-559, Japanese, 0039-906X, 1881-4751, 2015150618, 201502237250392230

糖尿病の筋細胞内Ca2+制御における筋線維タイプの影響
江島 弘晃; 狩野 豊
(一社)日本体力医学会, Dec. 2014, 体力科学, 63, 6, 559-559, Japanese, 0039-906X, 1881-4751, 2015150617, 201502250381076569

運動中の筋酸素分圧および肥大因子活性に及ぼす血流制限の影響
小出誠一郎; 須藤みず紀; 佐藤義昭; 安田智洋; 中島敏明; 狩野豊
(一社)日本体力医学会, Dec. 2013, 体力科学, 62, 6, 602-602, Japanese, 0039-906X, 1881-4751, 2014155712, 201402298763130887

ラット骨格筋の細胞内カルシウムイオンと熱ストレス
石黒 知定; 江島 弘晃; 狩野 豊
(一社)日本体力医学会, Dec. 2013, 体力科学, 62, 6, 521-521, Japanese, 0039-906X, 1881-4751, 2014155387, 201402211361913666

糖尿病骨格筋におけるCa2+制御タンパク質の影響
江島 弘晃; 小出 誠一郎; 中島 敏明; 狩野 豊
(一社)日本体力医学会, Dec. 2013, 体力科学, 62, 6, 499-499, Japanese, 0039-906X, 1881-4751, 2014155300, 201402238590315778

HITに対する骨格筋微小循環の適応
狩野 豊; 田中嘉法
杏林書院, Sep. 2013, 体育の科学, 63, 9, 695-700, Japanese, Introduction other, 0039-8985, 40019767892, AN00135823

Repetitive restriction of muscle blood flow enhances mtor signaling pathways in rat kaatsu mode
Toshiaki Nakajima; Tomohiro Yasuda; Seiichiro Koide; Nami Takano; Yoshiaki Sato; Yutaka Kano
Lippincott williams & wilkins, May 2013, Medicine and science in sports and exercise, 45, 5, 617-617, English, Summary international conference, 0195-9131, 1530-0315, WOS:000330469705026

運動中の筋酸素分圧動態に及ぼす血流制限の影響
小出誠一郎; 狩野豊; 須藤みず紀; 佐藤義昭; 安田智洋; 中島敏明
(一社)日本体力医学会, Dec. 2012, 体力科学, 61, 6, 582-582, Japanese, 0039-906X, 1881-4751, 2013162561, 201302245511544634

マイクロインジェクションによる糖尿病骨格筋のカルシウムイオン緩衝能力
江島 弘晃; 田中 嘉法; 狩野 豊
(一社)日本体力医学会, Dec. 2012, 体力科学, 61, 6, 579-579, Japanese, 0039-906X, 1881-4751, 2013162550, 201302230143164373

運動時エネルギー消費量の測定と酸素摂取動態
狩野 豊; 大河原一憲
杏林書院, Oct. 2012, 体育の科学, 62, 10, 751-756, Japanese, Introduction other, 0039-8985, 40019432985, AN00135823

Evaluation of exercise-induced muscle damage by bioimaging technique
SONOBE Takashi; INAGAKI Tadakatsu; KANO Yutaka
日本整形外科学会, 25 Jul. 2011, The Journal of the Japanese Orthopaedic Association, 85, 7, 415-419, Japanese, 0021-5325, 10031164140

末梢循環と筋の機能
狩野 豊
杏林書院, Apr. 2011, 体育の科学, 61, 4, 243-248, Japanese, Introduction other, 0039-8985, 40018738946, AN00135823

カルニチンの細胞内輸送の促進が骨格筋の持久性能力に及ぼす影響
増田和実; 古市泰郎; 高倉久志; 花井淑晃; 橋本健志; 狩野豊
Mar. 2011, （財）明治安田厚生事業団・第26回健康医科学研究助成報告書, 102-109, Japanese

In vivoイメージングによる骨格筋細胞内Ca²⁺動態の評価
曽野部崇; 狩野豊; 白井幹康
01 May 2010, 日本生理学雑誌, 72, 5, 144-145, Japanese, 0031-9341, 201002264477368530

Proanthocyanidinの経口摂取による筋組織の特異的なラジカル消去活性の変化
堀辰也; 増田和実; 古市泰郎; 田辺解; 狩野豊
2009, 北陸体育学会紀要, 44, 1-8

毛細血管からみた老化とトレーニング
狩野 豊
杏林書院, Feb. 2002, 体育の科学, 52, 2, 134-138, Japanese, Introduction other, 0039-8985, 40002276610, AN00135823

トップアスリートのMRI
狩野 豊; 秋間 広; 久野譜也
文光堂, Nov. 2000, 臨床スポーツ医学 臨時増刊号, 17, 33-37, Japanese, Introduction other, 0289-3339, 10009993386, AN10022550

MRIからみたジュニア・アスリートの筋特性: ジュニア・スプリンターを中心に.
塩崎知美; 宮丸凱史; 狩野豊; 久野譜也
文光堂, Nov. 2000, 臨床スポーツ医学 臨時増刊号, 17, 38-43, Japanese, Introduction other, 0289-3339, 10009993387, AN10022550

加齢に伴う上肢・下肢の動作速度変化
秋間, 広; 狩野, 豊; 石津政雄; 岡田守彦; 勝田, 茂; 久野譜也
NAP, Jan. 2000, 高齢者の生活機能増進法－地域システムと具体的ガイドライン－（岡田守彦, 松田光生, 久野譜也 編）, 319-321, Japanese

126.持久性トレーニングが心室壁の毛細血管形態に及ぼす影響
狩野豊; 七五三木聡; 増田和実; 坂戸英樹; 大森肇; 勝田茂
日本体力医学会, 01 Dec. 1996, 体力科學, 45, 5, 511-518, Japanese, 0039-906X, 110001947061

トップジュニア選手における大腿部筋組成の経時的変化―1992年から1993年まで―
勝田茂; 稲木光晴; 狩野豊; 藤本浩一; 久野譜也; 髙橋英幸; 宮丸凱史; 加藤謙一
1995, 筑波大学体育科学系紀要, 18, 141-148, Japanese, Peer-reviwed

こだわり抜く筋持久力増強運動
狩野豊
Japanese, Contributor, 筋持久力増強運動と循環系, 191p, 文光堂, Jun. 2023, 9784830647062

健康論 : 大学生のためのヘルスプロモーション
電気通信大学健康・スポーツ科学部会; 電気通信大学; 安藤, 創一; 大河原, 一憲; 岡田, 英孝; 小熊, 妙子; 狩野, 豊; 黒谷, 佳代; 栃木, 衛; 深澤, 浩洋; 星野, 太佑
Japanese, Contributor, 健康つくりの身体運動プログラム, viii, 178p, 道和書院, Mar. 2023, 9784810521443

医師・コメディカルのためのメディカルフィットネス
狩野 豊
Scholarly book, Japanese, Joint work, 骨格筋の生理学, 社会保険研究所, 13 Sep. 2019, 9784789468206

大学生のための「健康」論
狩野豊
Japanese, Joint work, 第5章 運動プログラム論, 道和書院, 01 Mar. 2016, 9784810521320

運動生理学20講：第３版
狩野 豊
Japanese, Joint work, 運動と末梢循環, 朝倉書店, 10 Apr. 2015

身体運動と呼吸・循環機能
狩野 豊
Japanese, Joint work, 毛細血管における酸素拡散と筋酸素摂取, 真興交易(株）医書出版部, Aug. 2012

身体トレーニング 運動生理学からみた身体機能の維持・向上
狩野 豊
Japanese, Joint work, セクション１０ トレーニングと循環 ５．毛細血管, 真興交易(株）医書出版部, Mar. 2009

体力とはなにかー運動処方のその前にー
狩野豊
Japanese, Joint work, 第４章 体力づくりプログラムの原則, ナップ, Mar. 2007

Oxford dictionary of sports science & medicine
狩野 豊
Dictionary or encycropedia, Japanese, Joint editor, 朝倉書店, 2006

人間の許容限界辞典
狩野 豊
Dictionary or encycropedia, Japanese, Joint work, 朝倉書店, 2005

健康論
狩野豊
Japanese, Joint work, 運動処方, 道和書院, Apr. 2004

筋の科学辞典-構造・機能・運動-
狩野 豊
Dictionary or encycropedia, Japanese, 朝倉書店, 2002

新運動生理学
狩野 豊
Japanese, Joint work, 毛細血管, 真興貿易医書出版部, Dec. 2001

運動と循環：研究の現状と課題
狩野 豊
Japanese, Joint work, 毛細血管の研究法, 筋活動と毛細血管形態の関連性, ナップ, Oct. 2001

運動生理・生化学辞典
狩野 豊
Dictionary or encycropedia, Japanese, 大修館書店, 2001

加齢にともなう毛細血管形態の変化と持久性トレーニングの影響. 高齢者の生活機能増進法：地域システムと具体的ガイドライン
狩野 豊; 松戸裕和; 古川博崇; 水田拓道
Japanese, Joint work, 高齢者の生活機能増進法を考える, ナップ，東京, Dec. 2000

運動生理学20講：第２版
狩野 豊
Japanese, Joint work, 運動と末梢循環, 朝倉書店, Apr. 1999

Assessment Of Intramuscular Blood Flow And Femoral Artery Blood Flow During Submaximal Knee Extensions: 181
I Kazuma; K Shiozawa; Y Kano; N Tanaka; K Katayama; H Akima
Poster presentation, English, Medicine & Science in Sports & Exercise 56 (10S), 45
01 Oct. 2024

カルシウムイオンの制御から見た骨格筋の機能と適応
狩野豊
Invited oral presentation, 第78回 日本体力医学会, Invited
02 Sep. 2024

間欠的等尺性膝伸展運動による筋内血流と大腿動脈血流変化の評価
泉主馬; 塩澤華奈; 狩野豊; 田中憲子; 片山敬章; 秋間広
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

レジスタンス運動後のラット骨格筋mRNA発現量の時間変化とその制御分子の探索
草野達哉; 曽谷祐太; 竹田怜央; 川田健太郎; 狩野豊; 星野太佑
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

17β-エストラジオールと雄マウス骨格筋の細胞内カルシウムイオン恒常性
近藤富貴; 狩野豊; 星野太佑
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

性差と性周期にともなう長時間運動前後のマウス骨格筋の遺伝子発現変動
香川美月; 田渕絢香; 草野達哉; 小野内摩耶; 星野太佑; 狩野豊
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

運動前の骨格筋への冷却刺激は運動による遺伝子発現を増強させるか？
狩野遼太郎; 竹田怜央; 安藤泰地; 草野達也; 狩野豊; 星野太佑
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

冷却刺激による細胞内カルシウムイオン濃度の上昇が筋分化へ及ぼす影響
薮田洋也; 長名シオン; 白川英樹; 星野太佑; 狩野豊
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

豊かな環境によるヒラメ筋の肥大と脳機能の関係性
須藤みず紀; 狩野豊; 安藤創一
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

ピルビン酸投与が内臓脂肪の炎症性サイトカインのmRNA発現量と糖代謝に与える影響
安藤泰地; 竹田怜央; 狩野遼太郎; 草野達哉; 野中雄大; 狩野豊; 星野太佑
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

脂肪細胞老化と関連する血中代謝物の探索と栄養素摂取への応用
竹田怜央; 狩野遼太郎; 福内友子; 三枝大輔; 狩野豊; 星野太佑
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

アシル基転移酵素LPGAT1/LPLAT7過剰発現マウス骨格筋における筋細胞内カルシウムイオン制御の変化
田渕絢香; 柏谷尚紀; 佐藤友紀; 三浦進司; 星野太佑; 狩野豊
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

マウス除神経モデルに対して局所温熱刺激がタンパク合成経路に与える影響
鵜川遥; 狩野豊; 池上諒
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

伸張性収縮モデルの骨格筋再生プロセスにおけるリアノジン受容体阻害の影響
馬場浩平; 田渕絢香; 須藤みず紀; 星野太祐; 狩野豊
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

フォトサーマル顕微鏡を用いた再生筋線維におけるミトコンドリアネットワークの評価
村上礼也; 田渕絢香; 小林孝嘉; 戸倉川正樹; 星野太佑; 狩野豊
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

ラット発育期における運動誘発性筋損傷抑制と細胞内カルシウムイオン動態
西嶌啓人; 田渕絢香; 星野太佑; 狩野豊
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

レジスタンス運動後のタンパク質合成経路の反応においてAMPKとのクロストークは重要な役割を果たす
曽谷祐太; 竹田怜央; 野中雄大; 狩野豊; 星野太佑
Oral presentation, Japanese, 第78回日本体力医学会大会
02 Sep. 2024

豊かな環境における自発性身体活動量と海馬における発現変動遺伝子の関係
須藤みず紀; 竹田怜央; 草野達哉; 星野太佑; 安藤創一; 狩野 豊
Poster presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

4 週間の高脂肪食摂取は筋収縮による遺伝子発現に影響を与える
根橋諒; 川田健太郎; 竹田怜央; 曽谷祐太; 草野達哉; 狩野豊; 星野太佑
Poster presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

伸張性収縮モデルの骨格筋再生プロセスにおけるリアノジン受容体阻害の筋線維径への影響
馬場浩平; 田渕絢香; 須藤みず紀; 星野太祐; 狩野豊
Poster presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

エストロゲンがマウス骨格筋の最大発揮張力に及ぼす影響
近藤富貴; 小野内摩耶; 田渕絢香; 香川美月; 星野太佑; 狩野豊
Poster presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

ラット発育期における安静時筋細胞内カルシウムイオン濃度のゆらぎ解析
西嶌啓人; 田渕絢香; 星野太佑; 狩野豊
Poster presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

筋芽細胞の分化過程での冷却感受性の変化
薮田洋也; 長名シオン; 白川英樹; 星野太佑; 狩野豊
Poster presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

マウス骨格筋除神経モデルに対する局所温熱負荷時の細胞内カルシウムイオンの恒常性
鵜川遥; 出牛逸輝; 池上諒; 星野太佑; 狩野 豊
Oral presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

ピルビン酸投与は高脂肪食摂取による糖代謝異常を改善させる
安藤泰地; 竹田怜央; 狩野遼太郎; 草野達哉; 野中雄大; 狩野豊; 星野太佑
Oral presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

性差と性周期にともなうマウス骨格筋の遺伝子発現変動
香川美月; 田渕絢香; 小野内摩耶; 草野達哉; 星野太佑; 狩野豊
Oral presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

フォトサーマル顕微鏡を用いた加齢による萎縮筋のミトコンドリアネットワーク評価
村上礼也; 田渕絢香; 小林孝嘉; 星野太佑; 狩野豊
Oral presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

老齢マウス骨格筋におけるヒト特異的CMAH遺伝子欠損の影響
田渕絢香; 竹田怜央; 星野太佑; 狩野豊
Oral presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

高強度インターバルトレーニングが骨格筋のペントースリン酸経路の酵素活性に与える影響
夏山龍伊; 狩野遼太郎; 安藤泰地; 狩野豊; 星野太佑
Oral presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

ラット骨格筋におけるレジスタンス運動後のmRNA発現量変動とタンパク質発現量の関係
草野達哉; 曽谷祐太; 竹田怜央; 幡野敦; 川田健太郎; 狩野豊; 星野太佑
Oral presentation, Japanese, 第32回日本運動生理学会
22 Aug. 2024

Morphometric evaluation of mitochondrial networks in regenerating myofibers using photothermal microscopy
R Murakami; A Tabuchi; T Kobayashi; D Hoshino; D C Poole; Y Kano
Oral presentation, English, Physiology 39 (S1), 766
21 May 2024

In vivo dynamics of hydrogen peroxide and regulation of antioxidant gene expression in mouse skeletal muscle under cooling stimulus
R Kano; R Takeda; H Shirakawa; D C Poole; Y Kano; D Hoshino
Oral presentation, English, Physiology 39 (S1), 744
21 May 2024

SERCA mediated thermogenesis during contraction-relaxation cycle in rat skeletal muscle in vivo
A Tabuchi; Y Tanaka; D C Poole; Y Kano
Oral presentation, English, Physiology 39 (S1), 610
21 May 2024

骨格筋の温度変化と細胞内カルシウムイオン恒常性
狩野豊
Invited oral presentation, 第2回和温療法学会学術集会, Invited
19 Nov. 2023
19 Nov. 2023

Suppressed Intracellular Calcium Ion Accumulation With Repeated Bouts Of Eccentric Contractions In Rat Skeletal Muscle: 643
Ayaka Tabuchi; Ryo Takagi; Yudai Kikuchi; Daisuke Hoshino; David C Poole; Yutaka Kano
Poster presentation, Medicine & Science in Sports & Exercise 55 (9S), 216-217, Peer-reviewed
01 Sep. 2023

Hydrogen Peroxide Dynamics In Cytoplasm And Mitochondria Of Mouse Skeletal Muscle During Concentric And Eccentric Contractions: 2099
Ryotaro Kano; Hideki Shirakawa; David C Poole; Daisuke Hoshino; Yutaka Kano
Invited oral presentation, Medicine & Science in Sports & Exercise 55 (9S), 682, Peer-reviewed
01 Sep. 2023

Assessment Of Intramuscular Blood Flow And Muscle Oxygenation During Intermittent And Incremental Muscle Contractions: 1665
K Izumi; K Yamamori; K Katayama; Y Kano; N Tanaka; H Akima
Oral presentation, English, Medicine & Science in Sports & Exercise 55 (9S), 553-554
01 Sep. 2023

Does Spontaneous Physical Activity Level Determine Cognitive Benefits From The Environmental Enrichment?: 1789
M Sudo; Y Kano; S Ando
Oral presentation, English, Medicine & Science in Sports & Exercise 55 (9S), 607
01 Sep. 2023

高圧高酸素処置が運動後の筋グリコーゲン回復に及ぼす影響
野中雄大; 竹田怜央; 竹田怜央; 小間陸嗣; 小間陸嗣; 狩野遼太郎; 狩野遼太郎; 柳下和慶; 芝口翼; 増田和実; 狩野豊; 星野太佑
体力科学
2023
2023 2023

Sex differences in intramuscular calcium ion dynamics induced by cooling and caffeine loading in mice model
Kousei Hayakawa; Ryo Takagi; Daiki watanabe; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 77th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
21 Sep. 2022

Visualization of mitochondrial Ca2+ dynamics in mouse during muscle contraction in the in vivo environment
Yoshinori Tanaka; Ayaka Tabuchi; Hideki Shirakawa; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 77th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
21 Sep. 2022

Morphological analysis of mitochondria in rat cardiomyocytes using photothermal microscopy
Reiya Murakami; Masaki Tokuragawa; Takayoshi Kobayashi; Nakata Kazuaki; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 77th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
21 Sep. 2022

Sex differences in intramuscular calcium ion dynamics during prolonged muscle contractions in mice
Maya Onouchi; Ayaka Tabuchi; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 77th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
21 Sep. 2022

Suppression of intracellular calcium ions after repeated bouts of eccentric contraction in rat skeletal muscle
Ayaka Tabuchi; Yudai Kikuchi; Ryo Takagi; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 77th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
21 Sep. 2022

Relationship between chronic heat stress protocols and skeletal muscle adaptation.
池上諒; 中島敏明; 豊田茂; 狩野豊
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 77th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
21 Sep. 2022

Pharmacological inhibition of ryanodine receptors immediately after eccentric contractions exercise effectively reduces exercise-induced muscle damage in rat skeletal muscle: 2101
A Tabuchi; Y Tanaka; R Takagi; D Poole; Y Kano
Oral presentation, English, Medicine & Science in Sports & Exercise 54 (9S), 615
01 Sep. 2022

The effects of environmental enrichment in the absence of wheel exercise on locomotion activity and anxiety-like behavior: 1991
M Sudo; Y Kano; S Ando
Oral presentation, English, Medicine & Science in Sports & Exercise 54 (9S), 524
01 Sep. 2022

Cmahの欠損は老齢マウスにおける脂肪組織の細胞老化およびインスリン感受性を改善させる
竹田怜央; 田渕絢香; 野中雄大; 狩野遼太郎; 狩野豊; 星野太佑
体力科学
2022
2022 2022

Spatiotemporal dynamics of intracellular calcium ions in skeletal muscle after eccentric contractions and relationship to muscle damage
Ayaka Tabuchi; Yoshinori Tanaka; Ryo Takagi; Hideki Shirakawa; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 76th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
17 Sep. 2021

Intracellular calcium ion concentration in repeated bout of eccentric contractions in rat skeletal muscle.
Yudai Kikuchi; Ayaka Tabuchi; Ryo Takagi; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 76th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
17 Sep. 2021

Simultaneous measurement of oxygen partial pressure dynamics in microvascular and interstitium using mouse skeletal muscle
Takuto Inoue; Ayaka Tabuchi; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 76th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
17 Sep. 2021

連続的な筋収縮負荷による筋細胞内グルコース動態の特徴
田中嘉法; 池上諒; 秋本崇之; 狩野豊
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 76th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
17 Sep. 2021

ラット骨格筋除神経モデルの安静時カルシウムイオン動態
出牛逸輝; 田渕絢香; 池上諒; 狩野豊
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 76th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
17 Sep. 2021

In vivo imaging of cooling-induced calcium dynamics in rat skeletal muscle
Ryo Takagi; Ayaka Tabuchi; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 76th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
17 Sep. 2021

A method for calculating lactate production rate using blood lactate concentration during exercise in mice
R Takeda; Y Nonaka; K Kakinoki; Y Kano; D Hoshino
Oral presentation, English, The FASEB Journal 35
May 2021

骨格筋線維のin vivoバイオイメージング
狩野豊
Invited oral presentation, Japanese, 第６回日本筋学会学術集会, 日本筋学会, Zoom リアルタイムオンライン, Domestic conference
21 Dec. 2020

骨格筋と健康寿命：筋細胞のバイオイメージング
狩野豊
Public discourse, Japanese, 2020年度 食品栄養科学 月例セミナー, 静岡県立大学 食品栄養科学部, Zoom リアルタイムオンライン, Domestic conference
20 Oct. 2020

Denervation produces lack of calcium ion homeostasis in skeletal muscle of the rat
Itsuki Jushi; Ryo Ikegami; Ayaka Tabuchi; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 75th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
24 Sep. 2020

Influence of icing after eccentric contractions on intracellular Ca2+ concentration and function in rat skeletal muscle
Ryo Takagi; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 75th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
24 Sep. 2020

Specific intracellular calcium ion dynamics following exercise-induced muscle damage
Ayaka Tabuchi; Yoshinori Tanaka; Ryo Takagi; Hideki Shirakawa; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 75th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
24 Sep. 2020

Effect of high-concentration lactic acid environment on sustained muscle contractions in rat skeletal muscle
Yoshinori Tanaka; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 75th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
24 Sep. 2020

Intracellular calcium ion concentration in repeated bout effect of eccentric contractions
Yudai Kikuchi; Ayaka Tabuchi; Ryo Takagi; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 75th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
24 Sep. 2020

Label-Free Super-Resolution Imaging of Mitochondria Structure of the Mouse Muscles with Photothermal Microscopy
Takayoshi Kobayashi; Kazuaki Nakata; Hiroki Tanaka; Yutaka Kano
CLEO: Applications and Technology AM2I. 4
10 May 2020

Effects of an acute 3‐h swimming exercise on insulin secretion capacity and its regulatory proteins of pancreatic islets in mice
Y Nonaka; R Takeda; Y Kano; D Hoshino
Oral presentation, English, The FASEB Journal 34 (S1), 1-1
Apr. 2020

Effects of Endurance Training on Lactate Uptake Capacity and Its Related Proteins in Skeletal Muscles in Mice
R Takeda; Y Nonaka; K Kakinoki; Y Kano; D Hoshino
Oral presentation, English, The FASEB Journal 34 (S1), 1-1
Apr. 2020

Preliminary experimental evaluation of microscopic imaging through thick biological tissues based on in-line phase-shift digital holography using near-infrared light
Manami Ohta; Shutaro Kodama; Kanami Ikeda; Yutaka Kano; Yoko Miyamoto; Wolfgang Osten; Mitsuo Takeda; Eriko Watanabe
English, Proceedings of SPIE - The International Society for Optical Engineering, SPIE, We previously proposed a three-dimensional microscopic imaging system for objects hidden behind scattering media using in-line phase-shift digital holography, which simultaneously captures amplitude and phase information. However, as the thickness of the scattering medium increases, the influence of scattering is enhanced, and the reconstructed image of the object behind the scattering medium deteriorates. In this paper, we report the evaluation of this image using a near-infrared light source with a wavelength of 780 nm that is capable of deep tissue penetration. A favorable microscopic image of the object behind the rat-skin sample of 912 μm-thickness was successfully reconstructed.
2020
2020 2020

温熱刺激の負荷時間の違いが骨格筋形態に与える影響：細胞質内カルシウムイオン濃度に着目して
池上諒; 中島敏明; 長谷川貴亮; 狩野豊
Oral presentation, Japanese, 第24回日本基礎理学療法学会学術大会, Japanese Society of Physical Therapy Fundamentals, Domestic conference
30 Nov. 2019

ラット骨格筋の温度低下が細胞内カルシウムイオン濃 度に及ぼす影響
高木領; 池上諒; 田渕絢香; 田中嘉法; 狩野 豊
Oral presentation, Japanese, 第24回日本基礎理学療法学会学術大会, Japanese Society of Physical Therapy Fundamentals, Domestic conference
30 Nov. 2019

Bioimaging science and skeletal muscle research
Yutaka Kano
Invited oral presentation, English, Beijing Institute of Technology, Academic Report of Advanced Innovation Center for Intelligent Robots and Systems, International conference
26 Sep. 2019

Calcium ion influx pathway during eccentric contractions in rat skeletal muscle
Ayaka Tabuchi; Hiroaki Eshima; Yoshinori Tanaka; Mizuki Sudo; Hidetaka Okada; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 74th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
19 Sep. 2019

Relationship between extracellular high-con- centration lactic acid environment and sus- tained muscle tension level
Yoshinori Tanaka; Takayuki Akimoto; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 74th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
19 Sep. 2019

Influence of cooling on intracellular calcium ion dynamics at rest in rat skeletal muscle
Ryo Takagi; Ryo Ikegami; Ayaka Tabuchi; Yoshinori Tanaka; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 74th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
19 Sep. 2019

Hydrogen peroxide in vivo bio imaging in skeletal muscle cells
Seiya Hirayama; Hiroshi Horikawa; Hideki Shirakawa; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 74th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
19 Sep. 2019

In vivo myocyte ATP imaging during muscle contraction in rat skeletal muscle
Xuebing Xiong; Chiho Magome; Hiromi Imamura; Yoshinori Tanaka; Shinji Miura; Yutaka Kano
Poster presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 74th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
19 Sep. 2019

Calcium ion accumulation dynamics in rat skel- etal muscle fibers by heat stress and muscle contraction
Ryo Ikegami; Hiroaki Eshima; Daisuke Hoshino; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 74th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
19 Sep. 2019

Microvascular permeability of skeletal muscle after hyperbaric oxygen: in vivo imaging study using two-photon laser scanning microscope
Tomoyo Asamura; Rie Shimotsu; Kazuki Hotta; Kazuyoshi Yagishita; Yutaka Kano
Oral presentation, Japanese, The Journal of Physical Fitness and Sports Medicine, The 74th Japanese Society of Physical Fitness and Sports Medicine, Domestic conference
19 Sep. 2019

The Onset of Exercise‐induced Microvascular Hyperpermeability is Delayed in Diabetic Skeletal Muscle: In Vivo Imaging Using Two‐Photon Laser Scanning …
K Hotta; R Shimotsu; K Masamoto; K Yagishita; BJ Behnke; DC Poole; Y Kano
Oral presentation, English, The FASEB Journal 33 (S1), 709.7-709.7
Apr. 2019

運動時の骨格筋組織における酸素ダイナミクス
狩野 豊
Invited oral presentation, Japanese, 第15回 乳酸研究会, 東京大学 駒場キャンパス, Domestic conference
16 Feb. 2019

血流制限下の低強度電気刺激はラットの骨格筋におけるMCT発現を増強する
中島 敏明; 安田 智洋; 小尾 正太郎; 豊田 茂; 井上 晃男; 狩野 豊
Japanese, 日本臨床生理学会雑誌, 日本臨床生理学会
Oct. 2018
Oct. 2018 Oct. 2018

後肢動脈結紮ラットにおける骨格筋微小血管の形態的・機能的特徴 ：2光子レーザー走査型顕微鏡を用いたin vivoイメージング
下津里恵; 堀田一樹; 正本和人; 柳下和慶; 狩野 豊
Oral presentation, Japanese, 体力科学, 第73回日本体力医学会, Domestic conference
Sep. 2018

糖尿病ラットにおける筋損傷後の微小血管透過性：2光子レーザー走査型顕微鏡を用いたin vivoイメージング
堀田一樹; 正本和人; 柳下和慶; 狩野 豊
Oral presentation, Japanese, 体力科学, 第73回日本体力医学会, Domestic conference
Sep. 2018

熱ストレスおよび筋収縮が筋細胞質内カルシウムイオン濃度に及ぼす影響
池上諒; 江島弘晃; 星野太佑; 狩野豊
Oral presentation, Japanese, 体力科学, 第73回日本体力医学会, Domestic conference
Sep. 2018

運動と加圧時における非活動筋の筋酸素分圧動態
中田直貴; 狩野豊
Oral presentation, Japanese, 体力科学, 第73回日本体力医学会, Domestic conference
Sep. 2018

in vivoバイオイメージングによる強縮刺激時の乳酸蓄積動態観察
田中嘉法; 秋本崇之; 狩野 豊
Oral presentation, Japanese, 体力科学, 第73回日本体力医学会, Domestic conference
Sep. 2018

フォトサーマル顕微鏡を用いた骨格筋細胞内のミトコンドリア形態観察
田中宏樹; 堀川大空; 中田和明; 小林孝嘉; 狩野豊
Oral presentation, Japanese, 体力科学, 第73回日本体力医学会, Domestic conference
Sep. 2018

損傷再生過程における細胞内カルシウムイオンダイナミクスとmTOR系の変化
田渕絢香; 白川英樹; 芝口翼; 杉浦崇夫; 狩野豊
Oral presentation, Japanese, 体力科学, 第73回日本体力医学会, Domestic conference
Sep. 2018

筋細胞内Ca2+調節と細胞内温度の関係性
堀川大空; 狩野豊
Oral presentation, Japanese, 体力科学, 第73回日本体力医学会, Domestic conference
Sep. 2018

運動時の骨格筋血流調節と毛細血管リモデリング
狩野豊
Invited oral presentation, Japanese, 第22回酸素ダイナミクス研究会, Domestic conference
Sep. 2018

Increased Exercise Activity In An Enriched Environment Improves Anxiety-like Behavior And Cognition.Microscopy
Sudo, Mizuki; Ando, Soichi; Kano, Yutaka; Nagamatsu Toshiya
English, Medicine & Science in Sports & Exercise, LIPPINCOTT WILLIAMS & WILKINS, TWO COMMERCE SQ, 2001 MARKET ST, PHILADELPHIA, PA 19103 USA
01 May 2018
01 May 2018- 01 May 2018

Skeletal Muscle Microvascular Permeability After Eccentric Contraction-Induced Muscle Injury: Novel In Vivo Imaging Using Two-Photon Laser Scanning Microscopy
Hotta, Kazuki; Behnke, Brad J; Masamoto, Kazuto; Shimotsu, Rie; Poole, David C; Kano, Yutaka
English, Medicine & Science in Sports & Exercise, LIPPINCOTT WILLIAMS & WILKINS, TWO COMMERCE SQ, 2001 MARKET ST, PHILADELPHIA, PA 19103 USA
01 May 2018
01 May 2018- 01 May 2018

Type I Diabetes Suppresses Intracellular Calcium Ion Influx by Heat Stress in Rat Skeletal Muscle
Ikegami, Ryo; Eshima, Hiroaki; Poole, David C; Kano, Yutaka
English, Medicine & Science in Sports & Exercise, LIPPINCOTT WILLIAMS & WILKINS, TWO COMMERCE SQ, 2001 MARKET ST, PHILADELPHIA, PA 19103 USA
01 May 2018
01 May 2018- 01 May 2018

Effects of Lactate Administration on Intracellular pH and Contractile Performance During Rhythmic Muscle Contractions
Tanaka, Yoshinori; Poole, David C; Kano, Yutaka
English, Medicine & Science in Sports & Exercise, LIPPINCOTT WILLIAMS & WILKINS, TWO COMMERCE SQ, 2001 MARKET ST, PHILADELPHIA, PA 19103 USA
01 May 2018
01 May 2018- 01 May 2018

筋収縮を支えるエネルギープラント;ミトコンドリアのNew Insights ミトコンドリアによる筋細胞内カルシウムイオンの調節
狩野 豊; 江島 弘晃
Japanese, 体力科学, (一社)日本体力医学会, https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2018&ichushi_jid=J00797&link_issn=&doc_id=20180209590013&doc_link_id=130006315705&url=http%3A%2F%2Fci.nii.ac.jp%2Fnaid%2F130006315705&type=CiNii&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00003_1.gif
Feb. 2018
Feb. 2018 Feb. 2018

Skeletal muscle hypertrophy induced by novel kaatsu rehabilitation and prevention of sarcopenia
Nakajima, Toshiaki; Yasuda, Tomohiro; Obi, Shotarou; Toyoda, Shigeru; Inoue, Teruo; Kano, Yutaka
English, CIRCULATION, LIPPINCOTT WILLIAMS & WILKINS, TWO COMMERCE SQ, 2001 MARKET ST, PHILADELPHIA, PA 19103 USA
14 Nov. 2017
14 Nov. 2017- 14 Nov. 2017

運動負荷・呼吸循環動態 ラット加圧モデルによる骨格筋各種蛋白質発現に及ぼす増強効果についての検討
中島 敏明; 安田 智洋; 小尾 正太郎; 豊田 茂; 井上 晃男; 狩野 豊
Japanese, 日本臨床生理学会雑誌, 日本臨床生理学会
Oct. 2017
Oct. 2017 Oct. 2017

ミトコンドリアによる筋細胞内カルシウムイオンの調節
狩野豊
Invited oral presentation, Japanese, 第72回日本体力医学会, Invited, Domestic conference
16 Sep. 2017

運動時における骨格筋の血流動態
狩野豊
Invited oral presentation, Japanese, 第68回日本体育学会, Invited, Domestic conference
08 Sep. 2017

ラット加圧モデルによる骨格筋各種蛋白質発現に及ぼす増強効果について
中島 敏明; 安田 智洋; 小尾 正太郎; 豊田 茂; 井上 晃男; 狩野 豊
Japanese, 日本臨床運動療法学会雑誌, (NPO)日本臨床運動療法学会
Sep. 2017
Sep. 2017 Sep. 2017

骨格筋細胞内におけるグルコース特異的な拡散動態
小泉柾夫; 狩野豊
Oral presentation, Japanese, 体力科学, 第72回日本体力医学会, Domestic conference
Sep. 2017

1型糖尿病モデルラット骨格筋における熱ストレス負荷時の細胞内カルシウムイオン動態：in vivoバイオイメージングによる解析
池上諒; 狩野豊
Oral presentation, Japanese, 体力科学, 第72回日本体力医学会, Domestic conference
Sep. 2017

活動筋および非活動筋における末梢酸素分圧の調節機構
中田直貴; 渡辺藍子; 狩野豊
Oral presentation, Japanese, 体力科学, 第72回日本体力医学会, Domestic conference
Sep. 2017

乳酸負荷が持久性の筋収縮における筋細胞内pHと筋発揮張力に及ぼす影響
田中嘉法; 狩野豊
Oral presentation, Japanese, 体力科学, 第72回日本体力医学会, Domestic conference
Sep. 2017

末梢動脈疾患のラットモデルにおける微小血管酸素分圧動態と筋持久力との関係性
渡辺藍子; 狩野豊
Oral presentation, Japanese, 体力科学, 第72回日本体力医学会, Domestic conference
Sep. 2017

骨格筋細胞内のカルシウム緩衝能力には性差が認められる
畠山幸二; 江島弘晃; 狩野豊
Oral presentation, Japanese, 体力科学, 第72回日本体力医学会, Domestic conference
Sep. 2017

蛍光プローブを用いた骨格筋細胞内のin vivo温度イメージング
堀川大空; 狩野豊
Oral presentation, Japanese, 体力科学, 第72回日本体力医学会, Domestic conference
Sep. 2017

運動誘発性筋損傷後の血管透過性の変化: 2光子レーザー顕微鏡を用いた観察
堀田一樹; 下津里恵; 狩野豊
Oral presentation, Japanese, 体力科学, 第72回日本体力医学会, Domestic conference
Sep. 2017

末梢動脈疾患モデルラットにおける骨格筋微小循環の機能的特徴 ：2光子レーザー顕微鏡を用いたin vivoイメージング
下津里恵; 堀田一樹; 正本和人; 狩野 豊
Oral presentation, Japanese, 第21回酸素ダイナミクス研究会, Domestic conference
Sep. 2017

In Vivo Intracellular Ca2+Dynamics Over 7 Days Following Eccentric Contractions In Rat Skeletal Muscle
Ayaka Tabuchi; Hideki Shirakawa; David C. Poole; Yutaka Kano
English, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, LIPPINCOTT WILLIAMS & WILKINS
May 2017
May 2017 May 2017

筋細胞内pH恒常性における細胞内緩衝機構の役割
田中嘉法; 狩野豊
Oral presentation, Japanese, 体力科学, 第71回日本体力医学会, Domestic conference
Sep. 2016

伸張性筋収縮後に観察される筋細胞内Ca2+ダイナミクス
田渕絢香; 狩野豊
Oral presentation, Japanese, 体力科学, 第71回日本体力医学会, Domestic conference
Sep. 2016

熱ストレスによるTRPV1を介した筋細胞内カルシウムイオン増加は筋収縮によって抑制される
真尾拓郎; 狩野豊
Oral presentation, Japanese, 体力科学, 第71回日本体力医学会, Domestic conference
Sep. 2016

運動時の微小血管および筋細胞間質の酸素分圧動態
渡辺藍子; 田中嘉法; 狩野豊
Oral presentation, Japanese, 体力科学, 第71回日本体力医学会, Domestic conference
Sep. 2016

in vivoバイオイメージングによる骨格筋細胞内グルコース拡散の評価
小泉柾夫; 狩野豊
Oral presentation, Japanese, 体力科学, 第71回日本体力医学会, Domestic conference
Sep. 2016

骨格筋細胞内のカルシウム緩衝能力における性差
畠山幸二; 江島弘晃; 狩野豊
Oral presentation, Japanese, 体力科学, 第71回日本体力医学会, Domestic conference
Sep. 2016

In Vivo Ca 2 Buffering Capacity Following Muscle Contractions In Skeletal Muscle Of Pgc-1α Overexpressing Mice
H Eshima; S Miura; D Poole; Y Kano
Oral presentation, English, Medicine & Science in Sports & Exercise48 (5), 747-747
01 May 2016

血流制限下の電気刺激によるトレーニングのラット骨格筋各種蛋白質発現に及ぼす効果
中島 敏明; 安田 智洋; 小尾 正太郎; 井上 晃男; 狩野 豊
Japanese, 日本臨床生理学会雑誌, 日本臨床生理学会
Oct. 2015
Oct. 2015 Oct. 2015

高温環境下の筋細胞内カルシウムイオンと筋収縮の関係性
真尾拓郎; 狩野豊
Oral presentation, Japanese, 体力科学, 第70回日本体力医学会, Domestic conference
Sep. 2015

細胞外のアシドーシス環境が筋細胞内pHに及ぼす影響
田中嘉法; 狩野豊
Oral presentation, Japanese, 体力科学, 第70回日本体力医学会, Domestic conference
Sep. 2015

Ca2+マイクロインジェクションによる筋細胞内Ca2+動態の特徴
脇坂馬里雄; 田中嘉法; 狩野豊
Oral presentation, Japanese, 体力科学, 第70回日本体力医学会, Domestic conference
Sep. 2015

筋細胞内Ca2+調節におけるミトコンドリアの役割：PGC-1αマウスによる検証
江島弘晃; 三浦進司; 狩野豊
Oral presentation, Japanese, 体力科学, 第70回日本体力医学会, Domestic conference
Sep. 2015

Muscle Contractions inhibit intracellular calcium homeostatic failure by Heat Stress
Takuro Mashio; Tomosada Ishiguro; Hiroaki Eshima; David C Poole; Yutaka Kano
Poster presentation, English, International Symposium on Human Adaptation to Environment and Whole-body Coordination, International conference
Mar. 2015

Rat brain and skeletal muscle microcirculation responses to hyperoxia
Naoki Shintani; Kohei Yamakoshi; David C Poole; Yutaka Kano
Poster presentation, English, International Symposium on Human Adaptation to Environment and Whole-body Coordination, International conference
Mar. 2015

筋細胞内Ca²⁺調節におけるミトコンドリアの役割:PGC-1αマウスによる検証
江島弘晃; 江島弘晃; 三浦進司; 狩野豊
体力科学
2015
2015 2015

I型糖尿病がラット脊柱僧帽筋の形態および代謝的特性に及ぼす影響
脇坂 馬里雄; 田中 嘉法; 江島 弘晃; 狩野 豊
Japanese, 体力科学, (一社)日本体力医学会
Dec. 2014
Dec. 2014 Dec. 2014

糖尿病の筋細胞内Ca2+制御における筋線維タイプの影響
江島 弘晃; 狩野 豊
Japanese, 体力科学, (一社)日本体力医学会
Dec. 2014
Dec. 2014 Dec. 2014

高気圧酸素曝露に対する糖尿病の循環調節機構
山越 康平; 柳下 和慶; 土持 裕胤; 稲垣 薫克; 白井 幹康; 狩野 豊
Japanese, 体力科学, (一社)日本体力医学会
Dec. 2014
Dec. 2014 Dec. 2014

糖尿病骨格筋の筋線維タイプが細胞内Ca2+恒常性に及ぼす影響
江島弘晃; 狩野豊
Oral presentation, Japanese, 体力科学, 第69回日本体力医学会
Sep. 2014

高気圧酸素曝露に対する糖尿病の循環調節機構
山越 康平; 柳下 和慶; 土持 裕胤; 稲垣 薫克; 白井 幹康; 狩野 豊
Oral presentation, Japanese, 体力科学, 第69回日本体力医学会
Sep. 2014

ラット骨格筋の細胞内カルシウムイオンと熱ストレス
石黒知定; 江島弘晃; 狩野豊
Oral presentation, Japanese, 体力科学, 第69回日本体力医学会
Sep. 2014

膜輸送体による細胞内pH制御と筋疲労の関係性
田中 嘉法; 狩野 豊
Oral presentation, Japanese, 体力科学, 第69回日本体力医学会
Sep. 2014

I型糖尿病がラット脊柱僧帽筋の形態および代謝的特性に及ぼす影響
脇坂馬里雄; 田中嘉法; 江島弘晃; 狩野豊
Oral presentation, Japanese, 体力科学, 第69回日本体力医学会
Sep. 2014

Heat Stress Impairs Intracellular Calcium Homeostasis In Rat Skeletal Muscle In Vivo
Tomosada Ishiguro; Hiroaki Eshima; David C. Poole; Yutaka Kano
English, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, LIPPINCOTT WILLIAMS & WILKINS
May 2014
May 2014 May 2014

Rat Skeletal Muscle Microvascular Oxygen Partial Pressure During Hyperbaric Oxygen Versus Air
Kohei Yamakoshi; Kazuyoshi Yagishita; David C. Poole; Yutaka Kano
English, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, LIPPINCOTT WILLIAMS & WILKINS
May 2014
May 2014 May 2014

Oral Administration Of BCAA Enhances Eccentric Training-Induced Adaptations In Rat Skeletal Muscle
Toshimi Suzuki; Hirofumi Miyata; Takao Sugiura; Akihiko Yamaguchi; Koichiro Hamada; Yutaka Kano
English, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, LIPPINCOTT WILLIAMS & WILKINS
May 2014
May 2014 May 2014

Contribution Of Membrane Transporters On H+ Buffering Capacity In The Rats Skeletal Muscle In Vivo
Yoshinori Tanaka; Tadakatsu Inagaki; David C. Poole; Yutaka Kano
English, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, LIPPINCOTT WILLIAMS & WILKINS
May 2014
May 2014 May 2014

Repeated Bouts Of Downhill Running Prevent Intense Eccentric Exercise-induced Muscle Damage In Type II Diabetes Rats
Mizuki Sudo; Soichi Ando; Yasuki Higaki; Yutaka Kano
English, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, LIPPINCOTT WILLIAMS & WILKINS
May 2014
May 2014 May 2014

The STZ-induced diabetes influences protein expression of the sarcoplasmic reticulum in the fast-twitch muscle fiber.
Hiroaki Eshima; Yutaka Kano
Poster presentation, English, The 91th Annual Meeting of the Physiological Society of Japan, International conference
17 Mar. 2014

SKELETAL MUSCLE HYPERTROPHY INDUCED BY NOVEL KAATSU REHABILITATION AND PREVENTION OF SARCOPENIA
T. Nakajima; T. Yasuda; S. Koide; Y. Sato; T. Morita; T. Tomaru; Y. Kano
English, CARDIOLOGY, KARGER
2014
2014 2014

ラット骨格筋の細胞内カルシウムイオンと熱ストレス
石黒 知定; 江島 弘晃; 狩野 豊
Japanese, 体力科学, (一社)日本体力医学会
Dec. 2013
Dec. 2013 Dec. 2013

糖尿病骨格筋におけるCa2+制御タンパク質の影響
江島 弘晃; 小出 誠一郎; 中島 敏明; 狩野 豊
Japanese, 体力科学, (一社)日本体力医学会
Dec. 2013
Dec. 2013 Dec. 2013

運動中の筋酸素分圧および肥大因子活性に及ぼす血流制限の影響
小出誠一郎; 須藤みず紀; 佐藤義昭; 安田智洋; 中島敏明; 狩野豊
Japanese, 体力科学, http://jglobal.jst.go.jp/public/201402298763130887
01 Dec. 2013
01 Dec. 2013- 01 Dec. 2013

Repetitive Restriction of Muscle Blood Flow Enhances mTOR Signaling Pathways in a Rat Model
Toshiaki Nakajima; Tomohiro Yasuda; Seiichiro Koide; Yoshiaki Sato; Nami Takano; Tatsuya Yamasoba; Issei Komuro; Yutaka Kano
English, CIRCULATION, LIPPINCOTT WILLIAMS & WILKINS
Nov. 2013
Nov. 2013 Nov. 2013

糖尿病骨格筋におけるCa2+制御タンパク質の影響
江島 弘晃; 小出誠一郎; 中島敏明; 狩野豊
Oral presentation, Japanese, 体力科学,第68回日本体力医学会
Sep. 2013

筋細胞内pH維持機構における筋線維間の相互作用
田中 嘉法; 狩野 豊
Oral presentation, Japanese, 体力科学,第68回日本体力医学会
Sep. 2013

運動中の筋酸素分圧および肥大因子活性に及ぼす血流制限の影響
小出誠一郎; 須藤みず紀; 佐藤義昭; 安田智洋; 中島敏明; 狩野豊
Oral presentation, Japanese, 体力科学,第68回日本体力医学会
Sep. 2013

ラット骨格筋の細胞内カルシウムイオンと熱ストレス
石黒知定; 江島弘晃; 狩野豊
Oral presentation, Japanese, 体力科学,第68回日本体力医学会
Sep. 2013

高気圧酸素環境下における筋微小循環系内の酸素分圧動態
山越康平; 柳下和慶; 小出誠一郎; 狩野豊
Oral presentation, Japanese, 体力科学,第68回日本体力医学会
Sep. 2013

骨格筋の毛細血管リモデリングと運動プログラム
狩野豊
Invited oral presentation, Japanese, 第68回日本体力医学会, 日本体力医学会
Sep. 2013

バイオイメージングによる筋機能の評価とその応用
狩野豊
Invited oral presentation, Japanese, 八王子先端技術センター医療イノベーションフォーラム
Jul. 2013

骨格筋組織の酸素代謝・微小循環の動態と適応
狩野豊
Invited oral presentation, Japanese, 第21回日本運動生理学会, 日本運動生理学会
Jul. 2013

Repetitive Restriction Of Muscle Blood Flow Enhances Mtor Signaling Pathways In Rat Kaatsu Mode
Toshiaki Nakajima; Tomohiro Yasuda; Seiichiro Koide; Nami Takano; Yoshiaki Sato; Yutaka Kano
English, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, LIPPINCOTT WILLIAMS & WILKINS
May 2013
May 2013 May 2013

バイオイメージングによる筋機能の評価とその応用
狩野豊
Invited oral presentation, Japanese, 電気通信大学脳科学ライフサポート研究センター 講演会
May 2013

In vivo imaging of intracellular Ca2+ after muscle contractions and direct Ca2+ injection in rat skeletal muscle in diabetes
Hiroaki Eshima; Yoshinori Tanaka; Takashi Sonobe; Tadakatsu Inagaki; David C. Poole; Yutaka Kano
English, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL
Apr. 2013
Apr. 2013 Apr. 2013

The effects of PGC-1 alpha on control of microvascular PO2 kinetics following onset of muscle contractions
Yutaka Kano; Shinji Miura; Osamu Ezaki; David C. Poole
English, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL
Apr. 2013
Apr. 2013 Apr. 2013

In vivo imaging of intracellular Ca2+ after muscle contraction and direct calcium injection in diabetic rat skeletal muscle.
Hiroaki Eshima; Yoshinori Tanaka; Takashi Sonobe; Tadakatsu Inagaki; David C. Poole; Yutaka Kano
English, Experimental Biology
Apr. 2013
Apr. 2013 Apr. 2013

Eccentric exercise-induced inflammatory response is augmented in type II diabetic skeletal muscle
Sudo, Mizuki; Eshima, Hiroaki; Ando, Soichi; Kano, Yutaka; Tanaka, Hiroaki; Higaki, Yasuki
English, FASEB JOURNAL
Apr. 2013
Apr. 2013 Apr. 2013

伸張性収縮による筋損傷と細胞内カルシウムイオン シンポジウム「筋肥大筋損傷の基礎研究」
狩野豊
Invited oral presentation, Japanese, 第157回日本体力医学会関東地方会, 第157回日本体力医学会関東地方会, Domestic conference
Mar. 2013

運動中の筋酸素分圧動態に及ぼす血流制限の影響
小出誠一郎; 狩野豊; 須藤みず紀; 佐藤義昭; 安田智洋; 中島敏明
Japanese, 体力科学, http://jglobal.jst.go.jp/public/201302245511544634
01 Dec. 2012
01 Dec. 2012- 01 Dec. 2012

運動中の筋酸素分圧，発揮張力，肥大因子タンパク発現に及ぼす血流制限の影響：ラット加圧モデルによる検証
小出誠一郎; 狩野豊; 須藤みず紀; 安田智洋; 髙野奈実; 佐藤義昭; 中島敏明
Oral presentation, Japanese, 日本心臓リハビリテーション学会,第18回日本心臓リハビリテーション学会学術集会
Jul. 2012

Myofiber apoptosis is suppressed by eccentric contractions under hypoxic stress.
Mizuki Sudo; Yutaka Kano
English, International Biochemistry of Exercise Congress (IBEC)
Jun. 2012
Jun. 2012 Jun. 2012

A Model For Understanding Eccentric Contractions-induced Muscle Damage: Bupivacaine-induced Elevations In Intramyocyte Ca2+
Tadakatsu Inagaki; Takashi Sonobe; David C. Poole; Yutaka Kano
English, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, LIPPINCOTT WILLIAMS & WILKINS
May 2012
May 2012 May 2012

In Vivo Imaging Of Intramyocyte Sodium Following Eccentric Contractions In Rat Skeletal Muscle
Takuma Kimura; Tdakatsu Inagaki; Yoshinori Tanaka; David C. Poole; Yutaka Kano
English, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, LIPPINCOTT WILLIAMS & WILKINS
May 2012
May 2012 May 2012

In Vivo Measurement of Intercellular pH and Contractile Performance During Repetitive Stimulation in Rat Skeletal Muscle
Yoshinori Tanaka; Tadakatsu Inagaki; Takuma Kimura; David C. Poole; Yutaka Kano
English, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, LIPPINCOTT WILLIAMS & WILKINS
May 2012
May 2012 May 2012

運動による筋組織損傷と循環機能の変化
狩野豊
Invited oral presentation, Japanese, 第2回高気圧酸素スポーツ医学研究会, 高気圧酸素スポーツ医学研究会
Mar. 2012

生理学から見たサブ２
狩野豊
Invited oral presentation, Japanese, 第24回ランニング学会大会, ランニング学会
Mar. 2012

運動と筋組織酸素分圧の関係
狩野豊
Invited oral presentation, Japanese, 第33回産学連携メディカルフロンティアセミナー, 東京大学医学部附属病院・22世紀医療センター
Mar. 2012

マイクロインジェクションによる糖尿病骨格筋のカルシウムイオン緩衝能力
江島弘晃; 田中嘉法; 狩野豊
体力科学
2012
2012 2012

単一線維レベルでのin vivo pHイメージング．
田中嘉法; 稲垣薫克; 木村卓磨; 狩野豊
Oral presentation, Japanese, 体力科学,第66回日本体力医学会
Sep. 2011

運動誘発性筋損傷および薬理学的筋損傷時の細胞内Ca2+動態の評価．
稲垣薫克; 田中嘉法; 木村卓磨; 曽野部崇; 狩野豊
Oral presentation, Japanese, 体力科学,第66回日本体力医学会
Sep. 2011

伸張性筋収縮後の細胞内ナトリウムイオンの可視化．
木村卓磨; 稲垣薫克; 田中嘉法; 狩野豊
Oral presentation, Japanese, 体力科学,第66回日本体力医学会
Sep. 2011

運動誘発性筋損傷 ‐ 再生過程におけるVEGFの発現パターン．
小野寺直也; 須藤みず紀; 山口明彦; 狩野豊
Oral presentation, Japanese, 体力科学,第66回日本体力医学会
Sep. 2011

加齢性筋肉減弱症(サルコペニア)に対する自発性走運動の効果―神経栄養因子の変化に着目して―
佐久間邦弘; 山口明彦; 須藤みず紀; 青井渉; 狩野豊
Japanese, 体力科学, http://jglobal.jst.go.jp/public/201102274271303222
01 Dec. 2010
01 Dec. 2010- 01 Dec. 2010

Gender influence on muscular Ca2+ accumulation pattern following repeated bout of isometric contractions in rat.
Tadakatsu Inagaki; Takashi Sonobe; David C. Poole; Yutaka Kano
English, 2010 ACSM conference on integrative physiology of exercise.
Sep. 2010
Sep. 2010 Sep. 2010

Time Course of VEGF-A mRNA Expression Following Eccentric Contractions in Rat Skeletal Muscle.
Naoya Onodera; Mizuki Sudo; Akihiko Yamaguchi; Yutaka Kano
English, 2010 ACSM conference on integrative physiology of exercise.
Sep. 2010
Sep. 2010 Sep. 2010

Involvement of myofiber apoptosis on eccentric contractions-induced damage and regeneration process in the diabetic rats.
Mizuki Sudo; Yutaka Kano
English, 2010 ACSM conference on integrative physiology of exercise.
Sep. 2010
Sep. 2010 Sep. 2010

The role of AMPK in skeletal muscle on microvascular PO2 kinetics following onset of muscle contraction.
Yutaka Kano; David C. Poole; Mizuki Sudo; Shinji Miura; Osamu Ezaki
English, 2010 ACSM conference on integrative physiology of exercise.
Sep. 2010
Sep. 2010 Sep. 2010

加齢性筋肉減弱症(サルコペニア)に対する自発性走運 動の効果ー神経栄養因子の変化に着目してー．
佐久間 邦弘; 山口 明彦; 須藤 みず紀; 青井 渉; 狩野 豊
Oral presentation, Japanese, 体力科学,第65回体力医学会, 体力科学59巻, p.600 (2010, 9).
Sep. 2010

運動誘発性筋損傷におけるVEGFmRNAの発現パターン．
小野寺 直也; 須藤 みず紀; 山口 明彦; 狩野豊
Oral presentation, Japanese, 体力科学,第65回体力医学会, 体力科学59巻, p.604 (2010, 9).
Sep. 2010

糖尿病骨格筋の損傷 再生機構における筋細胞アポトーシス発生．
須藤 みず紀; 狩野 豊
Oral presentation, Japanese, 体力科学,第65回体力医学会, 体力科学59巻, p.605 (2010, 9).
Sep. 2010

In vivoバイオイメージングよる筋細胞内ミトコンドリア分布の評価．
大熊 健裕; 稲垣薫克; 須藤 みず紀; 狩野豊
Oral presentation, Japanese, 体力科学,第65回体力医学会, 体力科学59巻, p.608 (2010, 9).
Sep. 2010

連続的な筋収縮後の細胞内pH動態.
稲垣薫克; 曽野部崇; 狩野豊
Oral presentation, Japanese, 体力科学,第65回体力医学会, 体力科学59巻, p.609 (2010, 9).
Sep. 2010

筋損傷後の回復過程におけるサテライトセルの動態．
増田 優香子; 山下 宏樹; 稲垣薫克; 須藤 みず紀; 狩野豊; 宮田浩文
Oral presentation, Japanese, 体力科学,第65回体力医学会, 体力科学59巻, p.621 (2010, 9).
Sep. 2010

Pain-producing Substances Changes In Rat Skeletal Muscle After Structual Damage
T Sakurai; Y Kano; O Kashimura
Oral presentation, English, Medicine & Science in Sports & Exercise 42 (5), 379
01 May 2010

骨格筋収縮時に見られる微小循環血流と酸素分圧動態の特徴
狩野豊
Invited oral presentation, Japanese, 第22回バイオエンジニアリング講演会, 日本機会学会
Jan. 2010

伸張性収縮誘発性筋損傷からの回復過程におけるAkt‐mTOR系の変化
芝口翼; 杉浦崇夫; 須藤みず紀; 狩野豊; 後藤勝正; 吉岡利忠
Japanese, 体力科学, http://jglobal.jst.go.jp/public/201002259046015700
01 Dec. 2009
01 Dec. 2009- 01 Dec. 2009

糖尿病ラットにおける筋収縮後の筋細胞内カルシウムイメージング
狩野豊; 曽野部崇; 稲垣薫克; 須藤みず紀
Japanese, 体力科学, http://jglobal.jst.go.jp/public/201002213979269516
01 Dec. 2009
01 Dec. 2009- 01 Dec. 2009

バイオイメージングによる運動誘発性筋損傷の評価
狩野豊
Invited oral presentation, Japanese, 第24回日本整形外科学会基礎学術集会, 日本整形外科学会
Nov. 2009

運動時の酸素供給・交換の統合的な調節．運動時の微小循環血流と酸素分圧動態
狩野豊
Invited oral presentation, Japanese, 第23回呼吸研究会, 第23回呼吸研究会, Domestic conference
Sep. 2009

高強度運動負荷後の骨格筋再生に及ぼす分岐鎖アミノ酸の影響
鈴木淑水; 狩野豊; 山口明彦; 岩下聡; 濱田広一郎
Oral presentation, Japanese, 体力科学,第64回体力医学会, 新潟 (2009, 9).
Sep. 2009

伸張性収縮誘発性筋損傷からの回復過程におけるAkt-mTOR系の変化
芝口翼; 杉浦崇夫; 須藤みず紀; 狩野豊; 後藤勝正; 吉岡利忠
Oral presentation, Japanese, 体力科学,第64回体力医学会, 新潟 (2009, 9).
Sep. 2009

糖尿病ラットにおける筋収縮後の筋細胞内カルシウムイメージング
狩野豊; 曽野部崇; 稲垣薫克; 須藤みず紀
Oral presentation, Japanese, 体力科学,第64回体力医学会, 新潟 (2009, 9).
Sep. 2009

血流制限強度とエキセントリック収縮誘発性筋損傷の関係
須藤みず紀; 狩野豊
Oral presentation, Japanese, 体力科学,第64回体力医学会, 新潟 (2009, 9).
Sep. 2009

疲労性筋収縮後の微小血管調節に対するαアドレナリン受容体遮断の影響
稲垣薫克; 曽野部崇; 狩野豊
Oral presentation, Japanese, 体力科学,第64回体力医学会, 新潟 (2009, 9).
Sep. 2009

In vivo imaging of intracellular calcium following skeletal muscle contractions in type I diabetes rat
Yutaka Kano; Takashi Sonobe; Tadakatsu Inagaki; Mizuki Sudo
English, International sports science network forum in Nagano 2009
Aug. 2009
Aug. 2009 Aug. 2009

Sex Difference In Intracellular Ca2+ Accumulation Following Eccentric Contractions of Rat Skeletal Muscle
Takashi Sonobe; Jun Nagata; Tadakatsu Inagaki; David C. Poole; Yutaka Kano
English, Medicine and Science in Sport and Exercise
May 2009
May 2009 May 2009

Eccentric Exercise Training-induced Skeletal Muscle Hypertrophy Is Augmented By Concomitant Blood Flow Restriction
Mizuki Sudo; Yutaka Kano
English, Medicine and Science in Sport Exercise
May 2009
May 2009 May 2009

Delayed Inflammation-regeneration Response Following Eccentric Contractions In Diabetic Rat Skeletal Muscle
Mai Shinohara; Mizuki Sudo; Yutaka Kano
English, Medicine and Science in Sport Exercise
May 2009
May 2009 May 2009

血流制限を伴うことによりエキセントリック収縮誘発性筋損傷は抑制される
須藤 みず紀; 狩野 豊
Japanese, 体力科學, 日本体力医学会, http://search.jamas.or.jp/link/ui/2009134170
01 Dec. 2008
01 Dec. 2008- 01 Dec. 2008

糖尿病ラット骨格筋の運動誘発性筋損傷と回復過程における形態特性
篠原 麻衣; 須藤 みず紀; 狩野 豊
Japanese, 体力科學, 日本体力医学会, http://search.jamas.or.jp/link/ui/2009134173
01 Dec. 2008
01 Dec. 2008- 01 Dec. 2008

連続的な筋収縮後の末梢血管動態と交感神経系の関与
稲垣 薫克; 曽野部 崇; 狩野 豊
Japanese, 体力科學, 日本体力医学会, http://search.jamas.or.jp/link/ui/2009134280
01 Dec. 2008
01 Dec. 2008- 01 Dec. 2008

伸張性収縮後の筋細胞内Ca²⁺蓄積には性差が生じる
曽野部崇; 稲垣薫克; 狩野豊
Japanese, 体力科学, http://jglobal.jst.go.jp/public/200902205035769938
01 Dec. 2008
01 Dec. 2008- 01 Dec. 2008

伸張性収縮後の筋細胞内Ca2+蓄積には性差が生じる
曽野部崇; 稲垣薫克; 狩野豊
Oral presentation, Japanese, 体力科学,第63回体力医学会, 大分 (2008, 9).
Sep. 2008

血流制限を伴うことによりエキセントリック収縮誘発性筋損傷は抑制される
須藤みず紀; 狩野豊
Oral presentation, Japanese, 体力科学,第63回体力医学会, 大分 (2008, 9).
Sep. 2008

連続的な筋収縮後の末梢血管動態と交感神経系の関与
稲垣薫克; 曽野部崇; 狩野豊
Oral presentation, Japanese, 体力科学,第63回体力医学会, 大分 (2008, 9).
Sep. 2008

糖尿病ラット骨格筋の運動誘発性筋損傷と回復過程における形態特性
篠原麻衣; 須藤みず紀; 狩野豊
Oral presentation, Japanese, 体力科学,第63回体力医学会, 大分 (2008, 9).
Sep. 2008

損傷骨格筋におけるNOと発痛関連物質の関係
桜井智野風; 鈴木健太; 南 広和; 柏木朋也; 島崎あかね; 狩野豊; 樫村修生
Oral presentation, Japanese, 体力科学,第63回体力医学会, 大分 (2008, 9).
Sep. 2008

Eccentric Contraction Induced Skeletal Muscle Damage Is Suppressed By Concomitant Blood Flow Restriction
Mizuki Sudo; Yutaka Kano
English, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, LIPPINCOTT WILLIAMS & WILKINS
May 2008
May 2008 May 2008

Myonuclear apoptosis occurs in regenerative process following eccentric contractions in rats
Mizuki Sudo; Yutaka Kano
English, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL
Apr. 2008
Apr. 2008 Apr. 2008

プロアントシアニジンの経口摂取が筋組織および血漿の活性酸素消去能力に及ぼす影響
堀 辰也; 増田 和実; 狩野 豊; 田辺 解; 永瀬 宗重
Japanese, 体力科學, 日本体力医学会, http://search.jamas.or.jp/link/ui/2008172144
01 Dec. 2007
01 Dec. 2007- 01 Dec. 2007

連続的な筋収縮後の細動脈および細静脈血管動態
稲垣 薫克; 曽野部 崇; 狩野 豊
Japanese, 体力科學, 日本体力医学会, http://search.jamas.or.jp/link/ui/2008172052
01 Dec. 2007
01 Dec. 2007- 01 Dec. 2007

糖尿病ラット骨格筋における運動誘発性筋損傷の組織学的特性
篠原 麻衣; 須藤 みず紀; 狩野 豊
Japanese, 体力科學, 日本体力医学会, http://search.jamas.or.jp/link/ui/2008171966
01 Dec. 2007
01 Dec. 2007- 01 Dec. 2007

ラット運動誘発性筋損傷の再生過程におけるアポトーシス発生
須藤 みず紀; 狩野 豊
Japanese, 体力科學, 日本体力医学会, http://search.jamas.or.jp/link/ui/2008171965
01 Dec. 2007
01 Dec. 2007- 01 Dec. 2007

筋収縮負荷後に起こる細胞内カルシウムイオン蓄積に対するチャネル阻害薬の影響
曽野部崇; 稲垣薫克; 狩野豊
Japanese, 体力科学, http://jglobal.jst.go.jp/public/200902206922271142
01 Dec. 2007
01 Dec. 2007- 01 Dec. 2007

筋収縮負荷後に起こる細胞内カルシウムイオン蓄積に対するチャネル阻害薬の影響
曽野部崇; 稲垣薫克; 狩野豊
Oral presentation, Japanese, 体力科学,第62回体力医学会, 秋田 (2007, 9).
Sep. 2007

ラット運動誘発性筋損傷の再生過程におけるアポトーシス発生
須藤みず紀; 狩野豊
Oral presentation, Japanese, 体力科学,第62回体力医学会, 秋田 (2007, 9).
Sep. 2007

糖尿病ラット骨格筋における運動誘発性筋損傷の組織化学的特性
篠原麻衣; 須藤みず紀; 狩野豊
Oral presentation, Japanese, 体力科学,第62回体力医学会, 秋田 (2007, 9).
Sep. 2007

連続的な筋収縮後の細動脈および細静脈血管動態
稲垣薫克; 曽野部崇; 狩野豊
Oral presentation, Japanese, 体力科学,第62回体力医学会, 秋田 (2007, 9).
Sep. 2007

プロアントシアニジンの経口摂取が筋組織および血漿の活性酸素消去能力に及ぼす影響
堀辰也; 増田和実; 狩野豊; 田辺解; 永瀬宗重
Oral presentation, Japanese, 体力科学,第62回体力医学会, 秋田 (2007, 9).
Sep. 2007

Accumulation of Intracellular Calcium following Repeated Isometric and Eccentric Contractions in Rat Skeletal Muscle in vivo.
Takashi Sonobe; Yutaka kano
English, Medicine and Science in Sport Exercise
May 2007
May 2007 May 2007

エキセントリック収縮によるラット骨格筋のアポトーシスおよびBcl-2, Bax 発現の経時的変化
須藤 みず紀; 狩野 豊
Japanese, 体力科學, 日本体力医学会, http://search.jamas.or.jp/link/ui/2007119708
01 Dec. 2006
01 Dec. 2006- 01 Dec. 2006

ラット後肢懸垂モデルにおける筋組織の酸素拡散機能と毛細血管形態
岩田 浩; 須藤 みず紀; 狩野 豊
Japanese, 体力科學, 日本体力医学会, http://search.jamas.or.jp/link/ui/2007119769
01 Dec. 2006
01 Dec. 2006- 01 Dec. 2006

ラット生体モデルによる筋収縮後の末梢血管動態と収縮パターンの関係
稲垣 薫克; 曽野部 崇; 狩野 豊
Japanese, 体力科學, 日本体力医学会, http://search.jamas.or.jp/link/ui/2007119768
01 Dec. 2006
01 Dec. 2006- 01 Dec. 2006

ラット生体モデルを用いた筋組織内カルシウムイオン動態の評価と筋収縮様式の影響
曽野部崇; 狩野豊
Japanese, 体力科学, http://jglobal.jst.go.jp/public/200902284436637020
01 Dec. 2006
01 Dec. 2006- 01 Dec. 2006

ラット生体モデルを用いた筋組織内カルシウムイオン動態の評価と筋収縮パターンの影響
曽野部崇; 狩野豊
Oral presentation, Japanese, 体力科学,第61回体力医学会, 神戸 (2006, 9).
Sep. 2006

エキセントリック収縮によるアポトーシス関連タンパク質発現の経時的変化
須藤みず紀; 狩野豊
Oral presentation, Japanese, 体力科学,第61回体力医学会, 神戸 (2006, 9).
Sep. 2006

連続的な筋収縮が活動電位の伝播に及ぼす影響：発揮張力，組織酸素分圧，筋温との対応関係に着目して
吹上史康; 狩野
Oral presentation, Japanese, 体力科学,第61回体力医学会, 神戸 (2006, 9).
Sep. 2006

筋組織の損傷―修復過程における酸素拡散機能と毛細血管形態
金平大輔; 狩野豊
Oral presentation, Japanese, 体力科学,第61回体力医学会, 神戸 (2006, 9).
Sep. 2006

ラット後肢懸垂モデルにおける筋組織の酸素拡散機能と毛細血管形態
岩田浩; 須藤みず紀; 狩野豊
Oral presentation, Japanese, 体力科学,第61回体力医学会, 神戸 (2006, 9).
Sep. 2006

ラット生体モデルによる運動時の末梢血管動態と収縮パターンの関係
稲垣薫克; 曽野部崇; 狩野豊
Oral presentation, Japanese, 体力科学,第61回体力医学会, 神戸 (2006, 9).
Sep. 2006

Role of Nitric Oxide in the Apoptosis of Structural Damage in Rat Skeletal Muscle
T Sakurai; Y Kano; H Ohno; LL Ji; TM Bes; T Izawa
Oral presentation, English, Medicine & Science in Sports & Exercise 38 (5), S124
01 May 2006

ラット骨格筋の運動誘発性アポトーシスにおける性差と運動様式の影響
須藤 みず紀; 狩野 豊
Japanese, 体力科學, 日本体力医学会, http://search.jamas.or.jp/link/ui/2006118378
01 Dec. 2005
01 Dec. 2005- 01 Dec. 2005

エキセントリック運動後のラット骨格筋における血管内皮細胞増殖因子の発現と酸素分圧レベル.
狩野豊
Oral presentation, Japanese, 体力科学,第60回体力医学会, 岡山 (2005, 9).
Sep. 2005

ラット骨格筋の運動誘発性アポトーシスにおける性差と運動様式の影響
須藤みず紀; 狩野豊
Oral presentation, Japanese, 体力科学,第60回体力医学会, 岡山 (2005, 9).
Sep. 2005

Dynamics of microcircular PO2 during muscle contraction on exercise-induced muscle damage model in rat
Yutaka Kano
Oral presentation, English, Comparative biochemistry and physiology
Aug. 2005

Effects of isometric and eccentric contractions on apoptosis of skeletal muscle in male and female rats.
Mizuki Sudo; Yutaka Kano
English, Medicine and Science in Sport Exercise
Jun. 2005
Jun. 2005 Jun. 2005

Expression Of Vascular Endothelial Growth Factor In Rat Skeletal Muscle Following Eccentric Contractions: 2007
Y Kano; N Yamada
English, Medicine & Science in Sports & Exercise 37 (5), S388
01 May 2005

Effects Of Type II Diabetes On Capillary Hemodynamics In Skeletal Muscle
DJ Padilla; P McDonough; BJ Behnke; Y Kano; KS Hageman; TI Musch; David C Poole
English, Medicine & Science in Sports & Exercise 37 (5), S359
01 May 2005

Microvascular oxygenation impairments in chronic heart failure (CHF) are exacerbated by concurrent type II diabetes (Dia)
DJ Padilla; P McDonough; BJ Behnke; Y Kano; KS Hageman; TI Musch; DC Poole
English, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL
Mar. 2005
Mar. 2005 Mar. 2005

運動後に生じる末梢循環の機能不全
狩野豊
Invited oral presentation, Japanese, 日本体育学会，東京支部第２回研究会, 日本体育学会，東京支部第２回研究会, Domestic conference
Nov. 2004

Effect of typeII diabetes on muscle microvascular oxygen pressure
Danielle Padilla Paul; McDonough; Brad J. Behnke; Yutaka Kano; K. Sue; Hageman. Timothy; I. Musch; David C. Poole
English, Physiologist
Oct. 2004
Oct. 2004 Oct. 2004

Apoptosis of skeletal muscle in male and female rats after eccentric contractions
Mizuki Oshima; Yutaka Kano
English, Physiologist
Oct. 2004
Oct. 2004 Oct. 2004

Effects of eccentric exercise on microcirculation and microvascular oxygen pressure in rat spinotrapezius muscle.
Yutaka Kano; Danielle Padilla; Brad J. Behnke; K. Sue Hageman; Timothy I. Musch; David C. Poole
English, Physiologist
Oct. 2004
Oct. 2004 Oct. 2004

運動誘発性筋損傷と微小循環
狩野豊
Invited oral presentation, Japanese, 第18回呼吸研究会, 呼吸研究会, Domestic conference
Sep. 2004

エキセントリック運動後の微小循環における機能不全
狩野豊
Oral presentation, Japanese, 体力科学
Sep. 2004

Effects of nitric oxide in recovery from structural damage in skeletal muscle
Tomonobu Sakurai; Yutaka Kano; Hideki Ohno; Li Li Ji; Thomas M Best; Tetsuya Izawa
English, Experimental Biology
Apr. 2004
Apr. 2004 Apr. 2004

Effects of Type II diabetes on capillary structure and function in skeletal muscle
DJ Padilla; P McDonough; Y Kano; KS Hageman; TI Musch; DC Poole
English, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL
Mar. 2004
Mar. 2004 Mar. 2004

Effect of type-2 diabetes on O-2 exchange in rat skeletal muscle
P McDonough; Y Kano; DJ Padilla; TI Musch; DC Poole
English, FASEB JOURNAL, FEDERATION AMER SOC EXP BIOL
Mar. 2004
Mar. 2004 Mar. 2004

Role of nitric oxide in recovery from lengthening contractions in rat skeletal muscle.
Tomonobu Sakurai; Yutaka Kano; Hideki Ohno; L.L.Ji; T. M. Best; Tetsuya Izawa
English, Medicine and Science in Sport and Exercise
Jun. 2003
Jun. 2003 Jun. 2003

Effect of different eccentric contraction numbers on morphological and functional aspects in rat skeletal muscle.
Yutaka Kano; Hirotaka. Furukawa; Yohei Fukurotani; Mizuki Ohshima; Taigo Onodera; Kenji Hirabayashi; Naoki Yamada
English, Medicine and Science in Sport and Exercise
Jun. 2003
Jun. 2003 Jun. 2003

運動誘発性の筋損傷と筋血流動態の変化
狩野豊
Oral presentation, Japanese, 体力科学
Oct. 2002

Changes in surface electromyogram parameters in rat skeletal muscle after strenuous eccentric exercise
Hirotaka Furukawa; Kazuyuki Mito; Kazumi Masuda; Kazuyoshi Sakamoto; Yutaka Kano
English, Medicine and Science in Sport and Exercise
May 2002
May 2002 May 2002

Time course of changes in capillarization in rat skeletal muscle after strenuous eccentric exercise
Yutaka Kano; Hirokazu Matsudo; Hirotaka Furukawa; Takudo Mizuta
English, Medicine and Science in Sport and Exercise
May 2002
May 2002 May 2002

Effects of aging on capillary number and luminal size in rat soleus and plantaris muscles
Yutaka Kano; Hirokazu Matsudo; Hirotaka Furukawa; Takudo Mizuta
English, Medicine and Science in Sport and Exercise
May 2001
May 2001 May 2001

Muscle function in 164 men and women aged 20-84 yr
H Akima; Y Kano; Y Enomoto; M Ishizu; M Okada; Y Oishi; S Katsuta; SY Kuno
English, MEDICINE AND SCIENCE IN SPORTS AND EXERCISE, LIPPINCOTT WILLIAMS & WILKINS, Purpose: The purpose of the present study was to investigate the effect of aging in men and women on muscle functional properties, i.e.. muscle force and force per unit of cross-sectional area (force/CSA). Methods: A total of 164 volunteers participated in this study and were divided into five groups according to their chronological age as follows: 20s (20-39 yr old), 40s, 50s, 60s, and 70s (70-84 yr old). Isokinetic (0, 60, 180, and 300 degreess(-1)) knee extensor and flexor peak torque, and CSA of the quadriceps femoris (QF) muscle of the mid-thigh were measured. Results: Peak torque during knee extension and flexion was inversely related to age in both men and women. This was the case irrespective of the speed of contraction in both genders (men: r = -0.797 to -0.756, all P < 0.001, women: r = -0.039 to -0.530, all P < 0.001). A significant correlation was observed between CSA of QF and peak torque during isometric knee extension in men (r = 0.827, P < 0.001) and women (r = 0.657, P < 0.001). During isometric contraction, the force/CSA exhibited a significant decrease with increasing age in men (r = -0.518, P < 0.001) but not in women (r = -0.207, NS). Conclusion: These results thus suggest that muscle strength losses would be mainly due to a decline in muscle mass in both genders, whereas age-related decline in muscle function in men may also be the result of neural factors, such as muscle recruitment and/or specific tension.
Feb. 2001
Feb. 2001 Feb. 2001

Capillary number and luminal size in rat skeletal muscle after strenous eccentric exercise
Yutaka Kano; Koji Sanpei; Junichi Nagasawa; Takudo Mizuta
English, APS conference: Integrative biology of exercise.
Sep. 2000
Sep. 2000 Sep. 2000

Capillary Network After Strenuous Eccentric Exercise
Yutaka KANO; Junichi NAGASAWA; Takuro MIZUTA
Oral presentation, Japanese, Advances in Exercise and Sports Physiology
Jul. 2000

老齢ラットの腹部大動脈における血管弛緩反応
狩野 豊; 長澤 純一; 田辺 匠; 水田 拓道
Japanese, 体力科學, 日本体力医学会
01 Dec. 1999
01 Dec. 1999- 01 Dec. 1999

血管の収縮弛緩に及ぼす身体不活動の影響
田辺 匠; 長澤純一; 狩野 豊; 井澤鉄也; 櫻井智野風; 大野秀樹; 水田拓道
Oral presentation, Japanese, 第8回日本運動生理学会，東京,Advances in Exercise and Sports Physiology
Oct. 1999

老齢ラットの腹部大動脈における血管弛緩反応
狩野 豊; 長澤純一; 田辺 匠; 水田拓道
Oral presentation, Japanese, 第54回日本体力医学会，熊本
Sep. 1999

The effect of strength training is potentially memorized and reinforced by retraining
Hajime Ohmori; Satoshi Shimegi; Koichi Fujimoto; Yutaka Kano; Mitsuharu Inaki; Masashi Miyamaru; shigeru Katsuta
English, Med. Sci. Sports Exerc., Japan Society of Exercise and Sports Physiology, http://dl.ndl.go.jp/info:ndljp/pid/10563715
May 1999
May 1999 May 1999

Capillary network and fiber size in rat skeletal muscle changes differentially to aging and training
Yutaka Kano; Satoshi Shimegi; Shigeru Katsuta
English, Med. Sci. Sports Exerc.
May 1999
May 1999 May 1999

男女スプリンターの下肢筋力が疾走速度に及ぼす影響-股関節の屈曲および伸展筋力に着目して-
渡辺信晃; 大山圭吾; 狩野 豊; 安井年文; 宮下 憲; 久野譜也; 勝田 茂
Oral presentation, Japanese, 第49回日本体育学会，愛媛
Oct. 1998

不活動モデルにおける骨格筋ミオグロビン濃度の変化
増田和実; 狩野 豊; 中野裕史; 勝田 茂
Oral presentation, Japanese, 第53回日本体力医学会，神奈川
Sep. 1998

女子スプリンターの疾走速度と筋横断面積との関係
渡辺信晃; 榎本好孝; 狩野 豊; 安井年文; 宮下 憲; 久野譜也; 勝田 茂
Oral presentation, Japanese, 第１回陸上競技医科学・コーチング国際会議，東京
Aug. 1998

Changes in capillary luminal diameter in rat soleus muscle after hindlimb suspension.
Yutaka Kano; Satoshi Shimegi; Hideyuki Takahashi; Kazumi Masuda; Shigeru Katsuta
English, Proceedings of 3rd Annual Congress of the European College of Sports Science. Manchester, England
Jul. 1998
Jul. 1998 Jul. 1998

Characteristics on muscle oxygenation in elderly men using neaar infrared spectroscopy
T Shiozaki; Y Kano; S Watanabe; R Ajisaka; M Ishizu; S Katsuta; M Okada; S Kuno
English, Medicine & Science in Sports & Exercise 30 (5), 72
01 May 1998

加齢にともなう毛細血管形態の変化と持久性トレーニングの影響
狩野豊; 坂戸英樹; 七五三木聡; 増田和実; 久野譜也; 勝田茂
Japanese, 体力科學, 日本体力医学会, http://ci.nii.ac.jp/naid/110001948055
01 Dec. 1997
01 Dec. 1997- 01 Dec. 1997

加齢に伴う股関節大腰筋の萎縮度の検討 : 大洋村健康づくりプロジェクト(2)
久野, 譜也; 金, 俊東; 塩崎, 知美; 佐々木, 心哉; 狩野, 豊; 石津, 政雄; 岡田, 守彦; 勝田, 茂
Japanese, Japanese Journal of Physical Fitness and Sports Medicine, The Japanese Society of Physical Fitness and Sport Medicine
Dec. 1997
Dec. 1997 Dec. 1997

加齢にともなう大腿部の筋量の変化及び性差 : 大洋村健康づくりプロジェクト(3)
大石, 芳江; 塩崎, 知美; 狩野, 豊; 坂戸, 英樹; 佐々木, 心哉; 勝田, 茂; 岡田, 守彦; 久野, 譜也
Japanese, Japanese Journal of Physical Fitness and Sports Medicine, The Japanese Society of Physical Fitness and Sport Medicine
Dec. 1997
Dec. 1997 Dec. 1997

高齢者における筋酸素利用能の特性 : 大洋村健康づくりプロジャクト(6)
塩崎, 知美; 狩野, 豊; 渡辺, 重行; 鰺坂, 隆一; 石津, 政雄; 勝田, 茂; 岡田, 守彦; 久野, 譜也
Japanese, Japanese Journal of Physical Fitness and Sports Medicine, The Japanese Society of Physical Fitness and Sport Medicine
Dec. 1997
Dec. 1997 Dec. 1997

高齢者の筋力および動作スピードに関する横断的研究 : 大洋村健康づくりプロジェクト(4)
秋間, 広; 狩野, 豊; 榎本, 好孝; 石津, 政雄; 勝田, 茂; 岡田, 守彦; 久野, 譜也
Japanese, Japanese Journal of Physical Fitness and Sports Medicine, The Japanese Society of Physical Fitness and Sport Medicine
Dec. 1997
Dec. 1997 Dec. 1997

スプリンターの大腰筋横断面積と疾走速度の関係
榎本, 好孝; 久野, 譜也; 狩野, 豊; 宮下, 憲; 山中, 邦夫; 宮丸, 凱史; 加藤, 謙一; 勝田, 茂
Japanese, Proceedings of the Congress of the Japanese Society of Physical Education, Japanese Society of Physical Education, Health and Sport Sciences
Aug. 1997
Aug. 1997 Aug. 1997

Relationship between the morphological features of thigh muscles and sprinting performance1257
Y Kano; H Takahashi; Y Morioka; H Akima; K Miyashita; S Kuno; S Katsuta
English, Medicine & Science in Sports & Exercise 29 (5), 220
01 May 1997

Relationships between muscle cross-sectional area and functional characteristics of hip flexor muscles and sprinting performance 1270
Y Enomoto; S Kuno; Y Kano; H Akima; K Miyashita; S Katsuta
English, Medicine & Science in Sports & Exercise 29 (5), 222
01 May 1997

持久性トレーニングが心室壁の毛細血管形態に及ぼす影響
狩野豊; 七五三木聡; 増田和実; 坂戸英樹; 大森肇; 勝田茂
Japanese, 体力科學, 日本体力医学会, http://ci.nii.ac.jp/naid/110001947061
01 Dec. 1996
01 Dec. 1996- 01 Dec. 1996

筋力トレーニング効果の保持と再トレーニングに対する応答
大森肇; 七五三木聡; 藤本浩一; 狩野豊; 稲木光晴; 宮丸凱史; 勝田茂
Japanese, 体力科學, 日本体力医学会, http://ci.nii.ac.jp/naid/110001947060
01 Dec. 1996
01 Dec. 1996- 01 Dec. 1996

一流ジュニア選手における大腿部筋特性の検討
久野, 譜也; 狩野, 豊; 萩原, 直樹; 高橋, 英幸; 大森, 肇; 船渡, 和男; 福永, 哲夫; 根本, 勇; 宮丸, 凱史; 勝田, 茂
Japanese, Proceedings of the Congress of the Japanese Society of Physical Education, Japanese Society of Physical Education, Health and Sport Sciences
Aug. 1996
Aug. 1996 Aug. 1996

スプリント能力と内転筋群の形態・筋力特性の関係
狩野, 豊; 高橋, 英幸; 森丘, 保典; 秋間, 広; 宮下, 憲; 久野, 譜也; 勝田, 茂
Japanese, Proceedings of the Congress of the Japanese Society of Physical Education, Japanese Society of Physical Education, Health and Sport Sciences
Aug. 1996
Aug. 1996 Aug. 1996

Effects of different intensity endurance training on capillary network in rat left ventricular myocardium.
狩野豊; 七五三木聡; 増田和実; 坂戸英樹; 大森肇; 勝田茂
体力科学
1996
1996 1996

低頻度のトレーニングが筋力発揮にもたらす効果
大森肇; 七五三木聡; 坂本啓; 狩野豊; 稲木光晴; 宮丸凱史; 勝田茂
Japanese, 体力科學, 日本体力医学会, http://ci.nii.ac.jp/naid/110001946450
01 Dec. 1995
01 Dec. 1995- 01 Dec. 1995

代償性筋肥大による骨格筋ミオグロビン濃度の変化
増田和実; 狩野豊; 七五三木聡; 勝田茂
Japanese, 体力科學, 日本体力医学会, http://ci.nii.ac.jp/naid/110001946453
01 Dec. 1995
01 Dec. 1995- 01 Dec. 1995

持久性トレーニングが毛細血管の数とその内腔面積に及ぼす影響
狩野豊; 七五三木聡; 増田和実; 坂戸英樹; 大森肇; 勝田茂
Japanese, 体力科學, 日本体力医学会, http://ci.nii.ac.jp/naid/110001946522
01 Dec. 1995
01 Dec. 1995- 01 Dec. 1995

代償性筋肥大を生じたラット骨格筋における毛細血管形態の適応
狩野豊; 七五三木聡; 増田和美; 大森肇; 勝田茂
Japanese, 日本体育学会大会号, 社団法人日本体育学会, http://ci.nii.ac.jp/naid/110001902343
10 Sep. 1995
10 Sep. 1995- 10 Sep. 1995

ジュニアスプリンターの大腿部筋形態・脚筋力と疾走能力の関係(04.運動生理学,一般研究発表)
狩野豊; 宮丸凱史; 加藤謙一; 秋間 広; 藤本浩一; 久野譜也; 勝田茂
Oral presentation, Japanese, Proceedings of the Congress of the Japanese Society of Physical Education, Japanese Society of Physical Education, Health and Sport Sciences
Aug. 1994
Aug. 1994 Aug. 1994

547 Morphological features of thigh muscle on elite junior sprinter
Y Kano; S Kuno; S Katsuta; M Miyamaru
English, Medicine & Science in Sports & Exercise 26 (5), S97
01 May 1994

トップジュニアの筋形態に関する研究 : トップジュニア・スプリンターにおける大腿部筋組成の経年的変化
狩野, 豊; 宮丸, 凱史; 秋間, 広; 久野, 譜也; 坂井, 悠二; 勝田, 茂
Japanese, Japanese Journal of Physical Fitness and Sports Medicine, The Japanese Society of Physical Fitness and Sport Medicine
Dec. 1993
Dec. 1993 Dec. 1993

Apr. 2023 - Present
Physiological Society of Japan

2005 - Present
The Japanese Society for Comparative Physiology and Biochemistry

Apr. 2002 - Present
Japan Society of Athletics

Apr. 2001 - Present
The Japanese Circulation Society

Jan. 2000 - Present
The American Physiological Society

Apr. 1995 - Present
Japan Society of Training Science for Exercise and Sport

Apr. 1994 - Present
Japan Society of Physical Education, Health and Sport Sciences

Apr. 1994 - Present
American College of Sports Medicine

1993 - Present
Japan Society of Exercise and Sports Physiology

Apr. 1992 - Present
Japanese Society of Physical Fitness and Sports Medicine

女性ホルモンが関与するミトコンドリアを中心としたオルガネラ連関による骨格筋適応
狩野 豊
日本学術振興会, 科学研究費助成事業, 電気通信大学, 基盤研究(B), 24K02827
01 Apr. 2024 - 31 Mar. 2028

骨格筋振動刺激はストレスから脳機能を守れるか？間質液に着目した新たな予防法の確立
須藤 みず紀; 高倉 久志; 安藤 創一; 狩野 豊
日本学術振興会, 科学研究費助成事業 基盤研究(B), 公益財団法人明治安田厚生事業団体力医学研究所, 基盤研究(B), 22H03477
01 Apr. 2022 - 31 Mar. 2026

Research on non-contact vital sign sensing technology for laboratory animals
孫 光鎬; 鈴木 哲; 狩野 豊
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (C), Coinvestigator, 23K11301
Apr. 2023 - Mar. 2026

Spatiotemporal evaluation of intramuscular blood flow during exercise by ultrasound power Doppler technique: comparison of elderly and young subjects
秋間 広; 片山 敬章; 狩野 豊; 田中 憲子; 小池 晃彦
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory), Nagoya University, Grant-in-Aid for Challenging Research (Exploratory), 22K19728
30 Jun. 2022 - 31 Mar. 2025

循環器疾患のサルコペニアとその対策としてのリハビリ法の開発・分子機構の解明
中島 敏明; 小尾 正太郎; 安田 智洋; 植松 梓; 福田 宏嗣; 豊田 茂; 柴崎 郁子; 狩野 豊
日本学術振興会, 科学研究費助成事業 基盤研究(B), 獨協医科大学, 基盤研究(B), 22H03457
01 Apr. 2022 - 31 Mar. 2025

Oxygen paradox and skeletal muscle remodeling based on muscle tissue oxygen levels
狩野 豊
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Challenging Research (Exploratory), Principal investigator, 23K18417
Jun. 2023 - Mar. 2025

運動によるインスリン抵抗性改善の分子基盤
秋本 崇之; 加藤 義雄; 狩野 豊
日本学術振興会, 科学研究費助成事業 挑戦的研究(開拓), 早稲田大学, 挑戦的研究(開拓), 本研究では，従来不可能であった様々な生物学的階層において，物理刺激に応じた骨格筋組織への糖取込み動態を可視化することで，運動によるインスリン抵抗性改善の分子メカニズムに迫るとともに，インスリン抵抗性に対する新たな治療戦略の創出を目指している． 本年度は，生細胞における糖代謝をモニタリングするため，糖輸送体GLUT4とpH依存的な蛍光タンパク質の融合遺伝子を構築し，各種培養細胞での検証を実施した．さらに検出感度を向上させるため，蛍光タンパク質に変異を導入して最適な遺伝子を探索する実験系の構築に着手した． 次にin vitroでの三次元培養によって骨格筋組織を構築し，これを上記の糖代謝動態の観察に用いるための実験系の最適化を実施した．現状において三次元培養組織を構築することは可能となったが，これをハイスループット化し，ドラッグスクリーニングを試行するためには，三次元組織培養系の更なる最適化が必要なことが明らかとなった． また同時にグルコース感受性蛍光タンパク質を用いて，筋収縮時の筋細胞内グルコース動態をin vivo環境下で経時的に観察する技法の確立を目的とし，収縮前後での細胞内グルコース動態の検証を実施した．, 20K20620
30 Jul. 2020 - 31 Mar. 2024

Measurement of oxygen transport in 3 phases of capillaries, interstitium, and cytoplasm in skeletal muscle
狩野 豊
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory), The University of Electro-Communications, Grant-in-Aid for Challenging Research (Exploratory),
本研究は，骨格筋組織内での酸素の時空間的な動態（酸素ダイナミクス）を解明することを目的とした．具体的には，毛細血管から細胞間質へ酸素が拡散し，細胞内に取り込まれ，ミトコンドリアの酸化的な代謝に利用されるプロセスの定量化を目標としている．先行研究では，筋収縮活動中の(1)血管内→(2)間質→(3)細胞内の3ステップでの酸素ダイナミクスを評価する研究モデルが存在していない．そこで，本研究は，「3ステップでの酸素ダイナミクスを同時に評価する測定技術を開発し，各々のステップでの酸素ダイナミクスを制御する生体システムの解明」に挑戦する． 本年度は，血管内（ステップ1）と間質内（ステップ2）の酸素ダイナミクスの同時計測モデルの構築を目的とした．実験動物モデル（ラット）を用いて，血管内（Oxygen probe R2）と間質内（Oxygen probe G4)に光学特性が異なる2つのプローブを同時に導入した．R2およびG4プローブは，一度励起されるとそのりん光は酸素分子のみによって消光される．したがって，りん光の減衰率が毛細血管または間質における酸素分圧の直接的な指標となる．プローブを導入後，酸素分圧がそれぞれ独立して，同時に観察できることが確認された．このモデルを用いて，筋収縮時の酸素ダイナミクスの定量化を実施している．, 21K19703
09 Jul. 2021 - 31 Mar. 2023

Multi-bioimaging of target molecules controlling skeletal muscle fiber adaptation
狩野 豊
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), The University of Electro-Communications, Grant-in-Aid for Scientific Research (B), 本研究は，トレーニングなどのストレスにともなう細胞適応を誘導するスイッチ（切替装置）の役割が細胞内のカルシウムイオン(Ca2+)と活性酸素種（ROS）のダイナミクス（細胞質中の空間的・時間的な濃度変化の連続）にあるという仮説を検証することを目的としている． 令和2年度は，Ca2+とROSのダイナミクスが運動刺激パターンを読み取り，スイッチのON/OFFの役割を担う可能性を明らかにするためのin vivoマルチバイオイメージング技法を構築することに着手した． 細胞内カルシウムイオン評価モデルでは，伸張性収縮後の筋損傷-再生過程ではタンパク質の分解や合成などの生理応答に着目し，これらを制御する細胞内Ca2+濃度の特徴的な時空間パターンの存在を調べた．その結果，伸張性収縮5時間後において，特に顕著なカルシウムイオンの変動を確認した．この動態は，タンパク質分解を活性化する特徴的な時空間パターンであることが考えられる． 細胞内ROS評価モデルでは，過酸化水素濃度に応じて蛍光強度が変化するタンパク質HyPerを利用した骨格筋in vivoイメージング法の確立を試みた．HyPerタンパク質を導入し，異なる濃度の過酸化水素滴下による過酸化水素動態をHyPerの蛍光強度比変化によってin vivo測定した．その結果，異なる濃度の過酸化水素の滴下により，筋線維毎に蛍光強度比の変動を画像化することに成功した．, 20H04074
01 Apr. 2020 - 31 Mar. 2023

Development of bioimaging technique for temperature measurement in skeletal muscle myofibers
Kano Yutaka
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory), The University of Electro-Communications, Grant-in-Aid for Challenging Research (Exploratory), Real-time analysis of intracellular temperature distribution leads to the elucidation of various cellular functions. This study was conducted to establish a technique to image temperature distribution in the in vivo environment without removing skeletal muscle from live animals. In the experiment, temperature-sensitive fluorescent probes were loaded into rat muscle cells. A model was constructed to observe the contraction-relaxation cycle by direct calcium ion injection into the cells, and temperature changes were observed in real time. This experimental model revealed that the sarcoplasmic reticulum, a cell organelle that regulates calcium ion in the cytoplasm, plays an important role in the muscle temperature changes during the contraction-relaxation cycle., 19K22800
28 Jun. 2019 - 31 Mar. 2022

Development of rehabilitation method applying physical stimulation as countermeasure for sarcopenia and elucidation of its underlying molecular mechanisms
中島 敏明; 佐久間 理吏; 小尾 正太郎; 井上 晃男; 安田 智洋; 福田 宏嗣; 豊田 茂; 柴崎 郁子; 狩野 豊
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Dokkyo Medical University, Grant-in-Aid for Scientific Research (B), 心血管疾患（cardiovascular disease: CVD）患者では、低栄養が、入院期間の長期化、再入院、死亡率と関連することが知られている。更に、高齢者でよくみられるサルコペニアの合併も死亡のリスクを増加させ、超高齢社会を迎えた現在では重要な健康問題となっている。CVD入院患者のサルコペニア、栄養障害、カヘキシア（悪液質）のマーカーとしての位相角(Phase angle: PhA)の臨床的有用性を検討した。サルコペニアは、男性31.6%、女性32.4%にみられた。PhAは、身体的機能及びSPPBスコアと正の相関を認めるとともに、CONUTスコア、Hb及びAlb値などの栄養指標と強く関連していることが判明した。さらに、CVD患者のサルコペニア、栄養障害、カヘキシアのマーカーとしてきわめて有用であると考えられた。 心臓手術後早期の患者の筋力と筋サイズに対する血流制限を伴う低強度筋力トレーニング（RT）（加圧RT）の安全性と効果を検証した。加圧RTグループは、週2回、3か月間、血流制限を伴う低強度RTを実施した。加圧RT中にあきらかな副作用はみとめず、CPK、D-ダイマーも明らかな上昇はみられなかった。大腿前面筋厚、SMI、歩行速度、膝伸展筋力は、加圧RTで3か月後に有意に増加した。低強度加圧RTは、心臓血管手術早期患者の筋力ならびに筋サイズを安全に増加させることが示された。 前年度のin vivo及びin vitroの検討では、温熱刺激は急性には細胞内Ca2+濃度上昇を、慢性には筋重量および筋サイズを増加させることを明らかにした。今回、I型糖尿病ラットでは、TRPV1タンパク質の発現と機能が低下し、熱ストレスによって誘発される細胞内Ca2+濃度上昇が抑制されていることが判明した。I型糖尿病ラットでは温熱療法による筋肥大効果が減弱している可能性がある。, 19H03981
01 Apr. 2019 - 31 Mar. 2022

Effects and Molecular Mechanisms of WAON Therapy on Cognitive Function and Muscle Strength Improvement in Elderly Heart Failure Patients
Toyoda Shigeru
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Dokkyo Medical University, Grant-in-Aid for Scientific Research (C), The effects of a WAON therapy on elderly patients with heart failure were examined. The results showed improvement in cognitive function. In terms of muscle strength and physical function, right and left knee extension muscle strength and SPPB were significantly increased and improved, and in SF36, vitality, daily role function (mental), and mental aspect were significantly improved. In the basic study, the effects of thermal stimulation on skeletal muscle were examined using cultured mouse skeletal myoblasts. Myh1, 2, and 4, which are markers of fast-twitch muscle, and Myh7, 12, and l3, which are markers of slow-twitch muscle, were all increased. In addition, thermal stimulation increased muscle weight and myofiber diameter in rats. These results indicate that the use of WAON therapy in elderly heart failure patients is effective in improving cognitive function and maintaining muscle strength, from both clinical and basic perspectives., 19K07895
01 Apr. 2019 - 31 Mar. 2022

骨格筋細胞の温度バイオイメージング技法の開発
狩野豊
Challenging exploratory research, Principal investigator, 19102069
30 Jun. 2019 - 31 Mar. 2021

筋細胞の適応を決定する運動後のカルシウムイオンダイナミクスの重要性
Kano Yutaka
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), The University of Electro-Communications, Grant-in-Aid for Scientific Research (B), The mechanism of skeletal muscle adaptation to maintain muscle mass and strength is not fully understood. This study investigated the possibility that intracellular calcium ion controls muscle mass and muscle function. It was revealed that intracellular calcium ion changes continuously for a while after muscle contractions. These changes were different depending on the type of exercise stress and male/female. The characteristic calcium ion dynamics may control skeletal muscle mass due to exercise stress., 16H03240
01 Apr. 2016 - 31 Mar. 2020

生体内で筋線維タイプを同定するバイオイメージング技法の開発
Kano Yutaka; KOBAYASHI Takayoshi; NAKATA Kazuaki; TANAKA Hiroki
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory), The University of Electro-Communications, Grant-in-Aid for Challenging Research (Exploratory), Different fiber types of skeletal muscle (fast-twitch/slow-twitch) have different characteristics of mitochondrial distribution and its shape. Photothermal (PT) microscopes are imaged utilizing light absorbing molecules contained in tissue. In this study, we attempted to evaluate muscle fiber type from morphological characteristics of mitochondria using PT microscope. The PT imaging luminance values of SDH stained and unstained in slow muscle fibers were higher than those of fast muscle fibers. Slow muscle fibers showed many elongated mitochondrial shapes. On the other hand, the dotted mitochondrial shapes were seen in fast muscle fibers. These features were also confirmed in untreated muscle samples without muscle tissue fixation. Our original PT microscopic observation was shown to allow mitochondrial imaging in untreated muscle tissue samples., 17K19897
30 Jun. 2017 - 31 Mar. 2019

多核細胞である骨格筋が筋線維タイプ変化を生じる機構の解明
狩野豊
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, The University of Electro-Communications, Grant-in-Aid for Challenging Exploratory Research, Principal investigator, The purpose of this study was to elucidate the mechanism of intracellular substances and nuclear information sharing of skeletal muscle fibers (multinuclear cells). This study clarified the existence of an active transport system to keep the intracellular level of glucose constant, and the existence of a mechanism to homogenize specific protein expression in the cell. As future research, it is necessary to elucidate the system that controls the mechanism by which skeletal muscle fibers retain uniform traits., 15K12665
01 Apr. 2015 - 31 Mar. 2018

A study on the changes of the time sequence of Aikido-fundamentals according to Aikido skill
KIKKAWA Kazutoshi; MITO Kazuyuki
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), The University of Electro-Communications, Grant-in-Aid for Scientific Research (C), In the present research, the time-sequence for Aikido-fundamentals among Aikido practitioners was analyzed by taking the biomechanical approaches. The main results were as follows: 1) In Katatedori-kokyuho, for most practitioners from 1st to 6th-dan, breath-out was observed while the switching step occurred concurrently with the arm lifting, followed by a breath-in. In this lifting stage, the advanced group (over 3rd-dan) performed the technique with a constant angle in the elbow, while the 1st-dan group bent and stretched the elbow. Therefore, these factors effected on the energy transmission onto the Uke. 2) In Tenkan-movement,the downword movement of center of gravity in mastery group (from 4th to 7th-dan) were smaller than value in beginners (under 1st-dan) at the primary stage. Furthermore, the range of center of pressure (COP) in the sole became smaller with increasing Aikido skill level. These facts during training can be used to make the teaching more efficient., 25350718
01 Apr. 2013 - 31 Mar. 2017

Skeletal muscle hypertrophy induced by KAATSU training and its molecular mechanisms and application to older adults with sarcopenia
Nakajima Toshiaki; KANO YUTAKA
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), Sarcopenia, the loss of muscle mass, is an important problem in the older population. We have performed several clinical and basic researches. (1) Effects of KAATSU training using low-intensity resistance exercise, using either resistance machines or elastic bands on muscle strength/mass and its safety in older adults. We found that KAATSU training, even using elastic bands for resistance, enhanced muscle activation and increases muscle strength and mass in older subjects. (2) Basic studies using rat KAATSU model. Acute low-intensity isometric electrical contractions under restrction of muscle blood flow (RMBF) significantly decreased microvascular pO2, and enhanced phosphorylation of mTOR signaling including ribosomal protein S6, compared with control. And, this EMS stimulation under RMBF significantly enhanced muscle strength/mass and enhanced skeletal muscle oxidative capacity, glucose/monocarboxylate transporter, and mitochondrial biogenesis in rat KAATSU model., 24300189
01 Apr. 2012 - 31 Mar. 2016

Visualization of mitochondrial behavior for oxygen environment in myocytes
KANO Yutaka
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, The University of Electro-Communications, Grant-in-Aid for Challenging Exploratory Research, The purpose of this study was construction of in vivo bio-imaging model to examine the relationship between intracellular oxygen level and mitochondrial behavior. This study focused on the possibility that the mitochondria move to capillary around for oxygen uptake at hypoxia.In this study, we were not able to build it about the mitochondrial labelling using the fluorescence protein to evaluate mitochondrial movement although a mitochondrial imaging under the in vivo environment was successful., 25560335
01 Apr. 2013 - 31 Mar. 2015

Effect of mechanical stress on calcium ion kinetics of the diabetes skeletal muscle
YUTAKA Kano
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), The University of Electro-Communications, Grant-in-Aid for Scientific Research (B), In diabetes mellitus force production in skeletal muscle is impaired and muscle fragility are increased, consequent to impaired calcium ion homeostasis. This study found that diabetes perturbs the calcium ion regulatory system such that resting calcium homeostasis following muscle contractions is compromised and elevations of calcium are exacerbated. This study considers the impact of diabetes on the capacity of skeletal muscle to regulate calcium, following muscle contractions and, in particular, the relationship between muscle fatigue and elevated calcium ion in a highly ecologically relevant circulation-intact environment. Given the profound microcirculatory dysfunction in diabetes this preparation presents the exciting imperative to investigate the relationships among microvascular function, blood-myocyte oxygen flux and calcium homeostasis as they relate to enhanced muscle fatigability and exercise intolerance., 22300221
01 Apr. 2010 - 31 Mar. 2014

Bioimaging technique to observe skeletal muscle metabolites in vivo
KANO Yutaka
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research, The University of Electro-Communications, Grant-in-Aid for Challenging Exploratory Research, Using an in vivo bioimaging model and microinjection technique, we tested homeostasis of intracellular when low pH solution was loaded in single fiber by microinjection. The intact spinotrapezius muscle of adult male Wistar rats was exteriorized and loaded with the fluorescent probe BCECF-AM. Muscle was loaded low pH solution by microinjection. This model offers a unique opportunity to investigate the consequences of experimental manipulations of pH on muscle buffering dynamics under close-to-physiological conditions, 23650403
2011 - 2012

Mechanisms of increase in exercise induced energy expenditure
MIURA Shinji; EZAKI Osamu; KAMEI Yasutomi; KANO Yutaka
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), National Institute of Health and Nutrition, Grant-in-Aid for Scientific Research (B), Trained subjects have a high VO2max due to a high cardiac output and high metabolic capacity of skeletal muscles. Because exercise training increases peroxisome proliferator-activated receptorγcoactivator 1α(PGC-1α) in skeletal muscle, PGC-1α-mediated changes may contribute to the improvement of exercise capacity and VO2max. There are three isoforms of PGC-1αmRNA. PGC-1α-b protein is a predominant PGC-1αisoform in response to exercise. In this study, we showed that PGC-1α-b induced increased mitochondrial biogenesis, capillaries, and fatty acid transporters in skeletal muscles may contribute to improved exercise capacity via an increase in fatty acid utilization., 21300240
2009 - 2011

The methods for evaluating the aerobic working capacity
FUKUBA Yoshiyuki; KOGA Shunsaku; FUKUOKA Yoshiyuki; HAYASHI Naoyuki; KANO Yutaka; MIURA Akira; YAMAOKA Masako
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Prefectural University of Hiroshima, Grant-in-Aid for Scientific Research (B), The main purpose of this study was to develop the new techniques of work rate forcing for estimating the aerobic working capacity of humans. The proposed techniques are based on ; 1) the sinusoidally fluctuated work rate forcing which simulates the non-steady state physical activities of daily life, and 2) the exponentially incremental work rate forcing, as an alternative way to the conventional ramp-mode exercise test With respect to the sinusoidal exercise, the responses of O2-cascade related variables(i. e. from pulmonary VO2 to O2-utlization in active muscle) and their coordination were examined. Furthermore, the physiological linkage, that is, circulatory adjustments among the O2-cascade related and non-related variables(including the cerebral and non-exercising limb circulations) were explored., 21370111
2009 - 2011

A biomechanical and exercise-physiological study of Aikido practice
KAZUTOSHI Kikaawa; HIDETAKA Okada; YUTAKA Kano
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), The University of Electro-Communications, Grant-in-Aid for Scientific Research (C), (1) The present study sought to perform a three-dimensional analysis of the "Tenchi-nage", a typical aikido technique. The elbow joint among the advanced trainee was rotating in the first half of the throw, and the elbow progressed greatly in the latter half of the throw. (2) The intensity of Aiki-do practice evaluated by Carvonen-way was 50% maximal oxygen intake practicing relative practice within peer with equal skill level and 60%VO2 practicing 20 times individual behind-fallings (Ushiro-ukemi). (3) The longitudinal changes of the measurements of physical fitness and motor ability tests among high school students who have been practicing aikido for 0.5 or 2.5 years were analyzed. Among the aikido male students, every measurement was developing in 2.5 years of school life or aikido life., 20500515
2008 - 2010

Interaction of myoglobin with mitochondria as an effective oxygen transport system
MASUDA Kazumi; HASHIMOTO Takeshi; HANAI Yoshiteru; KANO Yutaka; IWANAKA Nobumasa; KATO Yukio; SUGIURA Tomoko
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (A), Kanazawa University, Grant-in-Aid for Young Scientists (A), Cellular respiration is influenced by a wide range of mechanisms including the response of the cardiovascular and metabolic systems to meet the changing energy demands in muscle. The present study focused on myoglobin (Mb) expressed in the skeletal muscle and myocardial cells and hypothesized that Mb would closely associate with mitochondrial respiration during muscle contraction. The experimental evidences using in vivo muscle perfusion technique, suggested that Mb released its binding oxygen to mitochondria at onset of contraction and the response of Mb oxygen releasing was closely related with mitochondrial respiration. Furthermore, the immunohistochemical and immunoprecipitate analysis suggested that a part of Mb directly co-localized on mitochondria within a myocyte., 20680032
2008 - 2010

ヒトの運動時における筋線維動員パターンの新しい推定法
古賀 俊策; 狩野 豊
日本学術振興会, 科学研究費助成事業 挑戦的萌芽研究, 神戸芸術工科大学, 挑戦的萌芽研究, 活動筋の有酸素性代謝の発動が遅れるとエネルギー代謝は無酸素性に傾き、速筋線維がより多く動員される。現在、ヒトの運動時における筋線維動員パターンを非侵襲的に連続測定できる方法は、表面誘導筋電図法の他には見当たらない。今回の研究では、筋線維の種類によって微小循環-筋細胞レベルの酸素交換の動的な応答性が異なることに着目し、運動時における筋線維動員パターンを時間・空間分解能に優れた近赤外分光装置で推定する方法を検討した。 1)一定強度の運動開始後における活動筋の脱酸素化ヘモグロビン(HHb)の応答特性から動員される筋線維を推定した。動物筋線維における酸素交換特性を基にして検討した結果、HHbの増加速度(時定数)が遅く、かっ運動時の増加量(振幅)が小さい部位(例、大腿直筋)がより多くの遅筋線維、一方、HHbの応答が速く、振幅が大きい部位が速筋線維(例、外側広筋)を多く含むことが示唆された。 2)ランプ運動時における大腿筋のHHbの空間不均一性を計測した。さらに、動静脈酸素量差を反映するHHbを積分筋電図(筋肉の活動レベルを示す)と皮下脂肪厚で補正した。その結果、負荷強度の増加に伴ってHHbの空間不均一性は減少し、最大強度では筋肉間の酸素利用が均一になった。このため、運動強度の増加に伴って、筋線維動員パターンは空間的により均一になることが示唆された。また、自転車運動と膝伸展運動の比較では、HHbの空間不均一性に違いが見られた。, 20650103
2008 - 2009

バイオイメージングによる運動誘発性末梢循環不全の解明
狩野 豊
日本学術振興会, 科学研究費助成事業 若手研究(B), 電気通信大学, 若手研究(B), 運動誘発性の末梢循環不全について,細動脈レベルでの血管収縮弛緩応答性に着目して研究を進めた.筋組織への血液供給量は血管運動(vasomotion)による血管口径の変化によって調節されている.しかしながら,筋活動直後の血管運動と交感神経系の関連を調べた研究は少なく,運動直後の血管トーヌスにおける交感神経系の役割は明らかにされていない.そこで,本研究は次の仮説を検証した.1.連続的な筋収縮後の血管運動では漸増的に血管卜ーヌスが高まる.2.血管卜ーヌスの増加は交感神経系が関与している.本研究ではWistar系雄ラットの脊柱僧帽筋を対象としたin vivoモデルを用いた.100Hzの強縮刺激条件(4-6v, 0.7sec×50回,10セット,インターバル;5min)で筋収縮を誘発した.また選択的α1-アドレナリン受容体拮抗剤であるparazosin(1μM)を各セット前に脊柱僧帽筋に付加し,同様の手順で筋収縮刺激を負荷した.安静時と刺激後の組織画像を連続的に撮影し,細動脈および細静脈血管径を測定した.血圧および筋の発揮張力を同時に計測した.心拍数,平均血圧は筋収縮前後で顕著な変化を示さなかった.筋発揮張力において1セット時の初期値(5回の平均)を基準としたところ,1セット目に対して10セット目に67.6±8.4%低下した.prazosin付加では張力の低下率が小さかった(39.7±13.1%).また,細動脈において刺激直後に血管内径の減少が生じ,その程度はセット後半で増加した.一方,細静脈では筋収縮直後の内径縮小は観察されなかった.また,prazosinを付加した場合では,セット後半(10set)に観察される血管収縮が有意に抑制された.以上の結果から,連続的な強縮負荷とともに交感神経系の血管収縮作用による漸増的な血管トーヌスの増加が生じることが示唆された.運動後における交感神経系の血管トーヌスの増加は,活動組織への血液供給の遅延を生じるため,組織酸素分圧などの回復に影響を及ぼす可能性が考えられる.なお,研究計画に予定していた筋損傷を誘発する筋収縮と末梢循環動態との関連性については,実験モデルが確立できなかったため,検討することができなかった., 18700526
2006 - 2007

運動誘発性筋損傷と微小循環調節および酸素拡散機構
狩野 豊
日本学術振興会, 科学研究費助成事業 若手研究(B), 電気通信大学, 若手研究(B), 本研究はラットのダウンヒルランニング(DH)運動の1日と3日後の脊柱僧帽筋を対象に次の仮説を検証した.1.毛細血管内の赤血球流動性が低下する.2.運動性充血の低下によって,酸素交換能力が低下する.実験にはSD系雌ラット22匹を用いた.傾斜-14度,ランニング速度40m/minで5分間のランニングを2分間のインターバルで90分間負荷した.DHの1日(DH-1群)および3日後(DH-3群)に,脊柱僧帽筋の筋内酸素分圧動態と生体顕微鏡による微小循環動態を評価し,コントロール群(CONT群)と比較した.1.損傷筋における微小血管酸素分圧(PO2m)動態の評価:麻酔下において脊柱僧帽筋を露出し,酸素分圧測定装置に固定した.体温,筋温度を維持し,安静時ならびに電気刺激による筋収縮時の酸素分圧を経時的に評価した.2.生体顕微鏡による損傷筋の血流動態の評価:麻酔下において脊柱僧帽筋を剥離し,生体顕微鏡に設置した.安静時状態で,赤血球,白血球などの循環動態をモニターした.生体顕微鏡による観察結果から,筋損傷が部分的に認められた一方で,毛細血管の損傷は観察されなかった.ところが,安静下での赤血球流動はDHを行なった両群において有意に低下した.また,本研究では安静時のPO2mに群間で有意差は認められなかった.筋収縮状態では,電気刺激による筋収縮開始時からPO2mが低下するまでの時間および筋収縮開始からPO2mが低下して定常状態に達したときの値は,すべての群間で有意差は認められなかった.しかしながら,筋収縮中のPO2mの動態を示すパラメータである時定数はCONTよりDH群において有意に短かった.この時定数の有意な変化は,微小循環における酸素供給や交換(拡散)能力が損傷筋において損なわれていることを示している.本研究の結果は,一過性のエキセントリック運動負荷にともない血管内皮細胞や毛細血管の形態に損傷が見られない一方で,微小循環系の機能が低下している可能性を示唆している., 16700450
2004 - 2005

筋収縮と毛細血管損傷との関連性
狩野 豊
日本学術振興会, 科学研究費助成事業 若手研究(B), 電気通信大学, 若手研究(B), 高強度のエキセントリック運動は筋組織の損傷を引き起こす.損傷した組織の筋細胞は浮腫や壊死などを起こしていることが観察される.その一方で,微小循環網を形成している毛細血管の形態的な損傷はほとんど起こらないことが光学顕微鏡による形態観察によって明らかにされた(平成13年度研究実績).しかしながら,毛細血管を形成する血管内皮細胞の微細構造や微小循環血流量などの機能的な能力がエキセントリック運動によって受ける影響については不明である.そこで今年度はラットの運動誘発性の筋損傷モデルにおいて,骨格筋毛細血管の超微細構造を電子顕微鏡によって観察し,さらに運動負荷後(運動1,3,7日後)に見られる安静時の筋血流量の変化について検討した.血流量はマイクロソフェア(Microsphere : MS)法によつて調べた.その結果,光学顕微鏡観察と同様に損傷筋の毛細血管内皮細胞はエキセントリック運動によって構造的なダメージを受けていないことが観察された.また,筋血流量機能については,運動後7日までの安静時筋血流量が対照脚と比較して運動脚では有意に高い結果が示された.そして運動脚の血流量は運動後1,3,7日の順で経時的に低下することが示された.損傷した筋組織では運動3日後までに白血球の浸潤などが活発に見られることから,筋組織内における微小循環血流の高い状態が続いていることが考えられる.以上のように,本研究では損傷筋において毛細血管は正常な形態と機能が保たれていることが明らかにされた,これは運動負荷後に観察される筋血流量の確保に貢献しているものと推察できる., 13780018
2001 - 2002

加齢にともなう毛細血管数とその内腔形態の変化
狩野 豊
日本学術振興会, 科学研究費助成事業 奨励研究(A), 電気通信大学, 奨励研究(A), 本研究は加齢がもたらす血液循環能力の変化について,骨格筋毛細血管の形態的な側面より検討した.さらに,老齢期の動脈の機能的な側面についても検討を加えた.実験には3ヶ月月齢と19〜22ヶ月齢のwistar系雄性ラットを用いた.毛細血管の形態観察は生体灌流固定法を用いた.これは毛細血管が拡張した状態で観察できる利点をもっている.形態計測の結果,毛細血管数と毛細血管内腔の形態指標(毛細血管内腔の面積,周囲径,直径)には両群で統計的な有意差が見られなかった.その一方,筋線維の横断面積は老齢ラットが有意に低値を示した.このことは,この月齢時にあるラットの骨格筋では加齢にともなった筋委縮が生じていることを示している.したがって,毛細血管の加齢による形態変化は,筋線維の委縮といったような加齢現象よりも先行して起こらないことを示唆している.また,老齢ラットの動脈の拡張性について,アセチルコリンと一酸化窒素ドナー(NOC-18)に対する反応性より検討した結果,老齢ラットでは拡張の応答性が若齢ラットよりも顕著に低下していることが明らかとなった.以上のことから,加齢がもたらす血液循環能力の変化は,毛細血管のような微小循環系の形態変化よりも,動脈などの血流調整を行っている部分での機能変化の方が先行して生じる可能性が明らかになった., 10780013
1998 - 1999