Abstract
[Purpose] The purpose of this study was to investigate the effects of intermittent stretching exercise on disuse atrophy of the rat soleus muscle with respect to site and the change over time in the inhibitory effect on atrophy. [Subjects and Methods] Eighty-three 8-week-old male Wistar rats were divided into 3 groups: a control group which was reared under standard conditions (C0/3/7/10/14), a hind-limb suspension group (HS3/7/10/14), and a stretching exercise group (ST3/7/10/14). After the completion of each experimental period the soleus muscle was cut into proximal, middle, and distal samples, which were stained with hematoxylin and eosin, and the cross-sectional area (CSA) was measured. [Results] The CSA of ST14 was significantly greater than that of HS14. The reduction rate of the CSA in the middle and distal regions of ST14 was small compared to that of HS14. [Conclusion] The results suggest that disuse atrophy is altered over time by stretching exercise, and that there are differences in effect among the longitudinal sites of the soleus muscle.
