Tarnopolsky M A
Department of Pediatrics and Medicine, McMaster University, Hamilton, ON L8N 3Z5, Canada.
Appl Physiol Nutr Metab. 2009 Jun;34(3):348-54. doi: 10.1139/H09-022.
Aging is associated with a reduction in muscle mass and strength, which compromises functional independence. Skeletal muscle also shows an increase in mitochondrial dysfunction and oxidative stress in older adults. Resistance-exercise training is an important countermeasure for aging-associated muscle weakness. It has been shown that resistance-exercise training increases muscle strength and function in older adults, in association with a reduction in markers of oxidative stress and an improvement in mitochondrial function. Patients with sporadic mitochondrial cytopathies show an accumulation of mitochondrial DNA mutations and deletions in mature muscle, but not in satellite cells. Such patients have shown an activation of the satellite cells following myotoxic trauma and resistance, likely due to a fusion of the relatively quiescent satellite cells with mature muscle, which dilutes the mutational burden, a process called mitochondrial DNA shifting. Preliminary data strongly suggest that mitochondrial DNA shifting occurs in skeletal muscle from older adults following resistance-exercise training.
衰老与肌肉质量和力量的下降有关，这会损害功能独立性。老年人的骨骼肌还表现出线粒体功能障碍和氧化应激增加。抗阻训练是对抗与衰老相关的肌肉无力的重要对策。研究表明，抗阻训练可增强老年人的肌肉力量和功能，同时降低氧化应激标志物水平并改善线粒体功能。散发性线粒体细胞病患者在成熟肌肉中表现出线粒体DNA突变和缺失的积累，但在卫星细胞中则没有。此类患者在肌毒性创伤和抗阻后卫星细胞被激活，这可能是由于相对静止的卫星细胞与成熟肌肉融合，从而稀释了突变负担，这一过程称为线粒体DNA转移。初步数据有力地表明，抗阻训练后老年人的骨骼肌中会发生线粒体DNA转移。
