Proapoptotic factor Bax is increased in satellite cells in the tibialis anterior muscles of old rats.
Krajnak-K; Waugh-S; Miller-R; Baker-B; Geronilla-K; Alway-SE; Cutlip-RG
Muscle Nerve 2006 Dec; 34(6):720-730
Aging impairs the ability of muscle to adapt to exercise or injury. The goal of this study was to determine whether age-related changes in muscle adaptability could be the result of satellite cell apoptosis. Ten days after exposure to an injury protocol, estimates of edema in the exposed tibialis anterior muscles were higher in old (30 months) than young (3 months) rats, and isometric force levels were lower in old rats. Both young and old rats displayed an increase in MyoD labeling in the exposed muscle, indicating that injury induced satellite-cell activation. However, there were more MyoD-labeled cells that coexpressed the proapoptotic factor, Bax, in old than in young rats, suggesting that decrements in muscle recovery may be associated with an increase in satellite-cell apoptosis. Based on these findings we conclude that reducing satellite-cell apoptosis in aged animals may improve muscle recovery after injury.
Laboratory-animals; Animals; Animal-studies; Muscles; Muscle-contraction; Injuries; Exposure-levels; Exposure-assessment; Muscle-cells
Kristine Krajnak, Engineering and Controls Technology Branch, National Institute for Occupational Safety and Health, 1095 Willowdale Rd., MS 2027, Morgantown, West Virginia 26505, USA
Disease and Injury: Musculoskeletal Disorders of the Upper Extremities
Muscle & Nerve