Examination of Exercise Program for Improvement of Age-Related Decreases in Muscle Strength

本研究的目的是探讨运动计划，以改善与年龄有关的肌肉力量下降。80周龄雄性大鼠（n=10）进行了10周的运动与附着在笼子上的vlunary运行轮。根据每只动物每天的跑步距离增加车轮的负荷。在运动期之后，将比目鱼肌和跖肌取出并冷冻在液氮中。取10 μm厚连续横切片，进行肌纤维类型分类和SDH活性测定。运动后比目鱼肌各型肌纤维均出现肥大。跖肌浅层的快型纤维在运动后出现肥大。结果表明，选择性招募的快速型纤维的原因在最大的肌肉收缩在老年，这样的运动抑制了与年龄相关的肌纤维萎缩。

The purpose of this study was to examine exercise program for improvement of an age-related decrease in muscle strength. Eighty-week-old male rats(n=10)were exercised for 10 weeks with vluntary running wheefs attached to the cage. Load for the wheel were increased according to the daily running distance of each animal. After the exercise period, the soleus and plantaris muscles were removed and frozen in liquid nitrogen. Serial transverse sections, 10 μm thick, were cut and stained for ATPase and SDH activities for muscle fiber type classification and measurement of fiber SDH activity. All types of fibers in the soleus muscle showed hypertrophy after the exercise. Fast type of fibers at the superficial region in the plantaris muscle showed hypertrophy after the exercise. The results indicate that selective recruitment of fast type of fibers causes during the maximum muscle contraction at old ages, and that such an exercise inhibits an age-related muscle fiber atrophy.