| Project/Area Number |
06807007
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Environmental physiology (including Physical medicine and Nutritional physiology)
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| Research Institution | National Institute of Fitness and Sports in Kanoya |
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Principal Investigator |
OHIRA Yoshinobu National Institute of Fitness and Sports in Kanoya, Physiology and Biomechanics , Professor, 体育学部, 教授 (50185378)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1995: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1994: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Creatine / High-energy phosphates / Metabolic properties / Contractile properties / ラット / 骨格筋 / β-guanidinopropionic acid |
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| Research Abstract |
Effects of chronic depletion or loading of high-energy phosphate contents in skeletal muscles by feeding either beta-guanidinopropionic acid (beta-GPA) or creatine were studied in Wistar rats. The contractile properties in both soleus and extensor digitorum longus (EDL) were shifted toward slower type by feeding beta-GPA.The fatigue resistance in these muscles, especially EDL,was also improved. Transition of myosin isoforms in fast-twitch plantaris muscle was induced by administration of beta-GPA.Greater glucose uptake and the maximum binding capacity of beta-adrenoceptor, due to an increased receptor number, were further observed in the musles of beta-GPA group. Administration of creatine induced, generally, opposite phenomena. It is suggested that chronic depletion of high-energy phosphates stimulates the mitochondrial energy metabolism and shifts the muscle towerd slower type. It is also indicated that maintenance of high-energy phosphates at higher levels may not be essential for the greater fatigue resistance, if the capacity of adenosine triphosphate synthesis is improved.
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