内容記述 | In the present study, effects of stretch on muscle regeneration were morphologically examined in the soleus muscle injured by downhill running (eccentric exercise). In this study, 133 adult male ddY mice were divided into control (C: n=39), running (R: n=47) and stretch after running (RS: n=47) groups, and at 12hrs, 1, 2, 3, 5, 7 and 14 days after the running, these animals were sacrificed. To investigate sarcolemmal permeability, Evens blue dye (EBD) was beforehand injected into the peritoneal cavity of some mice. In the R group, area of muscle fibers was larger by 1 day after the running, and recovered to the control level after 5 days. In contrast, in the RS group, the area was smaller by 1 day and recovered to the control level by 2 days. After the running, narrow basophilic sarcoplasms appeared along the margin of the muscle fibers. Electron microscopically, these areas contained several mitochondria and ribosomes, suggesting that these morphological changes are regenerative rather than degenerative events. These areas began to appear earlier and muscle regeneration completed earlier in the RS group than the R group. Our findings suggested that stretch soon after the exercise can reduce delayed onset muscle soreness (DOMS), and promote muscle regeneration after the muscle injury. |