| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2006: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2005: ¥1,500,000 (Direct Cost: ¥1,500,000)
|
|---|
| Research Abstract |
To clarify the roles of local growth factors during exercise-induced passive stretching, we examined IGF-I Ea, MGF and myostatin mRNA expression in plantaris muscle following overload, denervation and hypophysectomy. Eight-week old rats were divided into 8 groups: normal control (NNCN), normal overloaded (NNOL), denervated control (NDCN)m denervated overloaded (NDOL), hypophysectomized control (XNCN), hypophysectomized overloaded (XNOL), hypophysectomized and denervated control (XDCN) and hypophysectomized and denervated overloaded (XDOL). The plantaris muscles were harvested at 1, 3 and 21 days after the treatments. The muscle samples were analysed IGF-I Ea, MGF and myostatin mRNA levels by using real-time PCR methods. The weights of plantaris muscle in NNOL and NDOL 21 days after the treatments were significantly higher than those of NNCN and NDCN, respectively. The weights in XNOL and XDOL were significantly higher than those of XNCN and XDCN, respectively. IGF-I Ea and MGF mRNA levels in NNOL and NDOL and XDOL 1 day after treatments were significantly higher than the control. After 3 days, IGF-I Ea andMGF mRNA levels in NNOL and NDOL, XNOL and XDOL were significantly higher than the control. Myostatin mRNA levels in NNOL and NDOL, XNOL and XDOL 1 and 3 days after the treatments were significantly lower than the control. We conclude that muscle enlargement due to exercise-induced passive stretching would be associated with the cooperative expression of IGF-I Ea, MGF and myostatin, and that the expression of IGF-I Ea, MGF and myostatin would be controled by growth hormone-independent manner.
|
