Repetitive stretching prevents muscle atrophy in denervated soleus muscle via Akt/mTOR/p70S6K pathways 周期的伸張刺激はAkt/mTOR/p70S6K経路を介して除神経によるヒラメ筋萎縮を抑制する

博士論文

This study was conducted to examine whether stretch-related mechanical loading on skeletal muscle can suppress denervation-induced muscle atrophy, and if so, to depict the underlying molecular mechanism. Denervated rat soleus muscle was repetitively stretched (every 5 sec for 15 min/day) for 2 weeks. Histochemical analysis showed that the cross-sectional area of denervated soleus muscle fibers with repetitive stretching was significantly larger than that of control denervated muscle (p<0.05). We then examined the involvement of the Akt/mammalian target of the rapamycin (mTOR) cascade in the suppressive effects of repetitive stretching on muscle atrophy. Repetitive stretching significantly increased the Akt, p70S6K and 4E-BP1 phosphorylation in denervated soleus muscle compared to controls (p<0.05). Furthermore, repetitive stretching-induced suppression of muscle atrophy was fully inhibited by rapamycin, a potent inhibitor of mTOR. These results indicate that denervation-induced muscle atrophy is significantly suppressed by stretch-related mechanical loading of the muscle through upregulation of the Akt/mTOR signal pathway.

名古屋大学博士学位論文 学位の種類:博士（医療技術学）（課程）学位授与年月日:平成21年3月25日