While the therapeutic role of exercise in catabolic dystrophic (dy) muscle remains controversial, regular submaximal exercise (SE) has been shown to preserve structure and function Using a hamster model (BIO 53.58) of muscular dystrophy, we examined the effects of 8 weeks SE, alone or with a high protein diet (HPD) on dy muscle protein metabolism, structure and function. SE (20 min b.i.d.; 4 m/min) reduced myofibrillar degradation but had little effect on protein metabolism, structure or function. However, the combination of SE + HPD reduced overall and myofibrillar proteolysis, increased protein synthesis, normalized fiber area distribution and preserved endurance in dy muscle to a greater extent than HPD or SE alone. In conclusion, SE + HPD appears effective in reducing proteolysis and preserving structure and function in dy hamster muscle. Group PD (nmol tyr) MD (nmol 3MH) PS (pmol/phe) PC(ug/mg) ΔEND (sec.) dy 61.7±6 0.42±06 52.8±4 116.9±7 -26 dy SE 52.5±5b 0.29±01a 48.8±6 110.7±9 -54 dy HPD 41.2±6a 0.20±.008a 59.5±9 119.7±11 -15 dy SE-HPD 34.5±5a 0.20±01a 65.8±4b 125.3±2 -18 NORM 30.1±5a 0.19±.009a 39.8±3 139.7±3a +2 PD=protein degradation; MD= myofibrillar degradation; PS=protein synthesis; PC=muscle protein content; ΔEND=change in endurance. a, b =minimum significance of p<0.05 vs untreated dy and untreated controls (NORM), respectively. (n=12).
|Original language||English (US)|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Molecular Biology