著者

Yuki Tamura Hideo Hatta

出版者

一般社団法人日本体力医学会

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.6, no.3, pp.151-158, 2017-05-25 (Released:2017-05-17)

参考文献数

50

被引用文献数

8

---

Heat stress treatment is a classic physical therapy, which is employed in the orthopedic field. In the field of physical fitness/sports science, morphological changes of skeletal muscle by heat stress have been well studied. In recent years, energy metabolic adaptations by heat stress have also been actively studied. In this review, we provide an overview of recent findings on heat stress-induced mitochondrial adaptations in skeletal muscles, and further discuss our unpublished data and recent findings in related research fields. First, we summarized heat stress-induced positive regulation of mitochondrial content and its underlying molecular mechanisms from perspectives of mitochondrial biogenesis and degradation. Consequently, we reviewed beneficial effects of heat stress on mitochondrial health in disused and aged muscles, focusing on mitochondrial stress response at the organelle level (mitochondrial selective autophagy; mitophagy) and molecular level (mitochondrial unfolded protein response). Finally, we overviewed future directions to better understand heat stress-induced mitochondrial adaptations in skeletal muscle.

著者

Yumiko Takahashi Yutaka Matsunaga Yuki Tamura Eiki Urushibata Shin Terada Hideo Hatta

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.3, no.5, pp.531-537, 2014-11-25 (Released:2014-12-05)

参考文献数

26

被引用文献数

4 6

---

Previous studies suggested that taurine (2-aminoethanesulfonic acid) administration enhances glucose uptake, one of the rate-limiting factors for glycogen synthesis. In this study, we investigated the effects of post-exercise taurine administration on glycogen repletion in skeletal muscle in ICR mice. In experiment 1, we orally administered either taurine (0.5 mg/g body weight) solution or physiological saline immediately after treadmill running at 25 m/min for 90 min. The serum free fatty acid (FFA) concentration at 60 min after the exercise was significantly higher in the taurine-treated group compared with the control group (p < 0.05). At 120 min after the exercise, the tibialis anterior muscle glycogen concentration in the taurine-treated group was significantly higher than that in the control group (p < 0.05). In experiment 2, we orally administered either glucose (1 mg/g body weight) solution or glucose solution containing taurine immediately after and at 60 min after the exercise. The area under the curve (AUC) for blood glucose concentration from 0 to 60 min after the exercise was significantly smaller in the taurine-treated group compared with the control group (p < 0.01). Our results show that post-exercise taurine administration enhances glycogen repletion in skeletal muscle. Higher skeletal muscle glycogen concentration by taurine administration may be partly due to the acceleration of glucose uptake. In addition, as the elevation of blood FFA level leads to an increase in fat oxidation, it is possible that a higher serum FFA concentration by taurine treatment is related to the sparing of carbohydrate for glycogen repletion.

著者

Yumiko TAKAHASHI Yutaka MATSUNAGA Yuki TAMURA Shin TERADA Hideo HATTA

出版者

Center for Academic Publications Japan

雑誌

Journal of Nutritional Science and Vitaminology (ISSN:03014800)

巻号頁・発行日

vol.63, no.5, pp.323-330, 2017 (Released:2017-12-08)

参考文献数

47

被引用文献数

4

---

Previous studies have shown that the short-term intake of a high-fat diet (HFD) impairs glucose metabolism. In this study, we investigated the influences of pre-exercise HFD intake for 3 d on post-exercise glycogen repletion in skeletal muscle in ICR mice. Mice received either an HFD (57% kcal from fat, 23% kcal from carbohydrate; HFD group) or standard laboratory chow (13% kcal from fat, 60% kcal from carbohydrate; Con group) for 3 d before exercise. Mice performed treadmill running at 25 m/min for 60 min and were orally administered a glucose (2 mg/g body weight) solution immediately after and at 60 min after exercise. A negative main effect of pre-exercise HFD intake was observed for skeletal muscle glycogen concentration from the pre-exercise phase to 120 min of post-exercise recovery (p<0.01). Blood glucose concentration in the HFD group was significantly higher than in the Con group at 120 min after exercise (p<0.01). No significant difference was observed in plasma insulin concentration. There were no significant between-group differences in the phosphorylation state of Akt Thr308, AMPK Thr172, AS160 Thr642, or glycogen synthase Ser641 or in glucose transporter 4 protein levels during post-exercise recovery. Our results suggest that the intake of a pre-exercise HFD for 3 d affects post-exercise glycogen repletion in skeletal muscle without impairing the insulin signaling cascade.