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Repetitive stretch suppresses denervation‐induced atrophy of soleus muscle in rats
Author(s) -
Agata Nobuhide,
Sasai Nobuaki,
InoueMiyazu Masumi,
Kawakami Keisuke,
Hayakawa Kimihide,
Kobayashi Kunihiko,
Sokabe Masahiro
Publication year - 2009
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.21103
Subject(s) - denervation , atrophy , soleus muscle , muscle atrophy , medicine , anatomy , physical medicine and rehabilitation , endocrinology , skeletal muscle
Abstract 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 s 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. Muscle Nerve, 2009