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Mechanosensitivity may be enhanced in skeletal muscles of spinal cord–injured versus able‐bodied men
Author(s) -
YararFisher Ceren,
Bickel C. Scott,
Kelly Neil A.,
Windham Samuel T.,
Mclain Amie B.,
Bamman Marcas M.
Publication year - 2014
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.24248
Subject(s) - isometric exercise , medicine , spinal cord injury , muscle hypertrophy , skeletal muscle , muscle contraction , p70 s6 kinase 1 , stimulation , myocyte , endocrinology , spinal cord , anatomy , signal transduction , biology , pi3k/akt/mtor pathway , microbiology and biotechnology , psychiatry
We investigated the effects of an acute bout of neuromuscular electrical stimulation–induced resistance exercise (NMES‐RE) on intracellular signaling pathways involved in translation initiation and mechanical loading–induced muscle hypertrophy in spinal cord–injured (SCI) versus able‐bodied (AB) individuals. AB and SCI individuals completed 90 isometric knee extension contractions at 30% of maximum voluntary or evoked contraction, respectively. Muscle biopsies were collected before, and 10 and 60 min after NMES‐RE. Protein levels of α7‐ and β1‐integrin, phosphorylated and total GSK‐3α/β, S6K1, RPS6, 4EBP1, and FAK were assessed by immunoblotting. SCI muscle appears to be highly sensitive to muscle contraction even several years after the injury, and in fact it may be more sensitive to mechanical stress than AB muscle. Heightened signaling associated with muscle mechanosensitivity and translation initiation in SCI muscle may be an attempted compensatory response to offset elevated protein degradation in atrophied SCI muscle. Muscle Nerve 50: 599–601, 2014