Ludatscher R, Silbermann M, Gershon D, Reznick A
Exp Gerontol. 1983;18(2):113-23. doi: 10.1016/0531-5565(83)90004-9.
C57BL/6J mice (6, 19 and 27 months old) were trained in an electrically driven treadmill for a total period of 10 weeks. The training program started with 5 min. run per day and reached a maximum of 30 min. per day. Light and electron microscopy examinations of the gastrocnemius muscle showed that in young animals endurance training did not evoke any appreciable changes. In contrast, both test animals and their controls in the old group revealed clear signs of muscle cell atrophy which for the most part was accompanied by focal loss of myofilaments, mitochondrial changes and an increase in the amount of endomyseal collagen fibrils. In the old-trained group, the most obvious abnormality comprised of multiplication of both the T-tubules and of the tubules of the sarcoplasmic reticulum. Consequently, most of these animals showed the formation of tubular aggregates in their gastrocnemius muscle. Hence, it appears that endurance training in old animals tends to enhance the regressive changes that accompany the aging process of mammalian skeletal muscle.
C57BL/6J小鼠（6个月、19个月和27个月大）在电动跑步机上训练了10周。训练计划从每天跑步5分钟开始，最多达到每天30分钟。对腓肠肌进行的光镜和电镜检查显示，在年轻动物中，耐力训练并未引起任何明显变化。相比之下，老年组的试验动物及其对照组均显示出明显的肌肉细胞萎缩迹象，大部分伴有肌丝局部丢失、线粒体变化以及肌内膜胶原纤维数量增加。在老年训练组中，最明显的异常包括横管和肌浆网小管的增殖。因此，这些动物中的大多数在其腓肠肌中出现了管状聚集体的形成。因此，似乎老年动物的耐力训练倾向于增强伴随哺乳动物骨骼肌衰老过程的退行性变化。
