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Muscle recovery after immobilization is improved by dietary supplementation with alpha‐hydroxyisocaproic acid (HICA)
Author(s) -
Lang Charles H.,
Magne Hugues,
Offord Elizabeth,
Breuille Denis
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.631.8
Subject(s) - muscle atrophy , endocrinology , medicine , chemistry , hindlimb , phosphorylation , protein degradation , muscle protein , gastrocnemius muscle , skeletal muscle , stimulation , alpha (finance) , biochemistry , biology , surgery , construct validity , patient satisfaction
We posited that αHICA, a leucine metabolite, will slow the loss or improve recovery of muscle mass in response to disuse. Adult rats were fed a diet supplemented with αHICA or an isocaloric isonitrogenous control diet. Disuse was produced by unilateral hindlimb immobilization (casting) for 7 d, using the contralateral muscle as control, or the cast removed and muscle recovered for 14 d. Casting decreased gastrocnemius mass which was associated with reduced muscle protein synthesis (MPS) and S6K1 phosphorylation, but increased proteasome activity and atrogin‐1 and MuRF1 mRNA. αHICA did not prevent casting‐induced muscle atrophy, but the typical decrement in MPS was not detected. αHICA did not alter the immobilization‐induced increase in proteasome activity and atrogene expression. After 14 d of recovery, muscle mass had returned to control values only in αHICA‐fed rats and this was associated with increased MPS and S6K1 and 4EBP1 phosphorylation in previously immobilized muscle. Proteasome activity and atrogene content remained at control levels during recovery and were not affected by αHICA. Our data suggest αHICA supplementation does not slow muscle loss produced by disuse, but does speed recovery in part by maintaining increased MPS.