离心运动对大鼠骨骼肌细胞增殖和波形蛋白表达的时序性影响

Sequential effects of eccentric exercise on the skeletal muscle cell proliferation and vimentin expression in rats

背景:骨骼肌损伤后是通过肌卫星细胞的增殖形成新核来生长和修复的,但关于骨骼肌细胞增殖和波形蛋白表达的关系很少报道。目的:探讨骨骼肌细胞增殖与波形蛋白表达的关系以及运动性骨骼肌微损伤后修复的机制。设计、时间和地点:随机对照动物实验,于2007-12/2008-09在湖南师大运动人体科学实验中心完成。材料:健康成年8周龄雄性SD大鼠50只,随机分成对照组和运动后即刻、运动后3h、运动后24h和运动后48h组,每组10只大鼠。方法:运动组大鼠进行重复3d的力竭性离心运动,力竭模型采用跑台运动,速度为16m/min,坡度为-16°,持续运动至力竭,对照组为正常大鼠,未做运动。主要观察指标:运动组分别于运动后即刻,3,24,48h取材,对照组一次性取材,免疫组织化学法检测各组大鼠肱三头肌内侧头不同恢复时相增殖细胞核抗原PCNA的表达和波形蛋白的表达。结果:骨骼肌细胞增殖出现时序性变化,运动后即刻增殖指数显著大于对照组,运动后24h达到峰值,运动后48h增殖指数有所下降。骨骼肌细胞中波形蛋白表达出现时序性,而且其免疫反应分值的时序性与增殖指数出现一致性,但与增殖指数不具有相关性。结论:3d重复性力竭离心运动后骨骼肌细胞增殖和波形蛋白的表达出现时序性变化。波形蛋白的表达与肌细胞增殖具有一定的关系,但不是惟一的影响的因素。

BACKGROUND： The regeneration and repair of skeletal muscle after injury relies on the new nucleus formed through muscle satellite cell proliferation. However, there are few reports on the relationship between the skeletal muscle cell proliferation and the vimentin expression. OBJECTIVE： To explore the relationship between the skeletal muscle cell proliferation and the vimentin expression, as well as the mechanism underlying the repair of exercise-induced skeletal muscle micro-injury. DESIGN, TIME AND SETTING： A randomized controlled animal experiment was done at the Sports Human Science Experimental Center in Hunan Normal University between December 2007 and September 2008. MATERIALS： A total of 50 male SD rats, aged 8 weeks, were randomly divided into a control group and a training group which were subdivided in to four groups at the time points of immediate post-exercise, hour 3, hour 24 and hour 48 post-exercise, with 10 ones in each of the five groups. METHODS： Rats in the training group underwent 3 days of repetitive exhausting eccentric exercise on a treadmill of -16° slope at the speed of 16 m/min. Rats in the control group underwent no running. MAIN OUTCOME MEASURES： Rats in the training group was taken for measurement immediate, 3 hours, 24 hours and 48 hours post-exercise respectively. Immunohistochemistry was adopted to determine the proliferating coil nuclear antigen （PCNA） A expression and the vimentin expression in medial head of triceps brachii muscle cells in each group at different phases of repair. RESULTS： The skeletal muscle cell showed sequentially-changed proliferation. The proliferation index of the training group was significantly higher than that of the control group immediately post-exercise. At hour 24 post-exercise, it reached the peak. Hour 48 post-exercise saw the decreased proliferation. The expression of vimentin also exhibits a sequential change after exercise. Moreover, its immunoreaction score changed with time in the same direction with the proliferation index, but there is no correlation between the two. CONCLUSION： Three days of repeated exhausting eccentric exercise can induce the sequential changes of skeletal muscle cell proliferation and vimentin expressions. Vimentin expression has some kinds of correlations with skeletal muscle cell proliferation, but it is not the only factor that matters.