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

这项研究的目的是检查锻炼计划是否能改善与年龄相关的肌肉力量下降。80周龄的雄性大鼠（n=10）在笼子上固定自主跑轮，进行10周的运动。根据每只动物每天的奔跑距离，增加车轮的负荷。运动结束后，取出比目鱼和跖肌，置于液氮中冷冻。取10 μm厚的连续横切面进行atp酶和SDH活性染色，用于肌纤维类型分类和纤维SDH活性测定。运动后比目鱼肌各类型纤维均出现肥大。运动后足底肌浅表快型纤维出现肥大。结果表明，选择性招募快速型纤维导致了老年肌肉收缩的最大化，这种运动抑制了与年龄相关的肌肉纤维萎缩。

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.