大强度离心运动大鼠不同时相骨骼肌结构及血白细胞介素6、肌酸激酶、肌酸激酶同工酶的变化

Skeletal muscle structure at different phases after eccentric exercise and changes of blood interleukin-6,creatine kinase and creatine kinase isoenzyme in rats

背景:运动预处理可在一定程度上减轻运动性骨骼肌微损伤,从而避免延迟性肌肉酸痛的发生。目前应用白细胞介素6和CK-MM评定骨骼肌微细损伤还较缺少实验性研究。目的:观察运动预处理对大鼠大强度离心运动后不同时相骨骼肌结构损伤及血液白细胞介素6、肌酸激酶和CK-MM变化的影响。设计、时间及地点:随机对照动物实验,2006/2007在成都体育学院动物实验室完成。材料:成年健康雌性SD大鼠80只,体质量(231.3±12.44)g。每组又随机分别分为运动前和运动后即刻、运动后24,48,72h5个亚组,每组8只。方法:无预处理组:除对运动前组外其他大鼠进行一次速度19～21m/min,坡度为-16°的90min的跑台运动。运动预处理组:进行2周离心跑台训练,2周后,除运动前组外,其他大鼠进行一次性跑台运动,运动方式同无预处理组。主要观察指标:一次性离心运动后即刻、24,48和72h观察比目鱼肌结构及血液白细胞介素6、肌酸激酶、CK-MM的变化。结果:运动后两组大鼠比目鱼肌均出现损伤性改变,尤以无预处理组更为明显,且以运动后24～48h较为严重。无预处理组运动后即刻血浆白细胞介素6显著增高,随后逐渐下降,72h再次显著增高。运动预处理组运动后即刻略降低,随后逐渐升高,于48h达峰值。运动后运动预处理组血浆白细胞介素6水平低于无预处理组。运动前运动预处理组肌酸激酶和CK-MM均低于无预处理组。运动后无预处理组、运动预处理组两组肌酸激酶和CK-MM先升后降,除运动后72h外,运动预处理组CK和CK-MM水平及变化幅度低于无预处理组。结论:运动预处理有助于减轻离心运动导致的骨骼肌超微结构损伤及运动应激所引起的相关血液指标变化。肌酸激酶和CK-MM活性水平的个体差异较大,更适用于个体自身的纵向比较。

BACKGROUND： Exercise preconditioning can lighten exercise-induced muscle damage, thereby to avoid delayed onset muscle soreness. At present, experimental research is scarce that apply interleukin-6 （IL-6）, creatine kinase （CK） and creatine kinase isoenzyme （CK-MM） to evaluate skeletal muscle damage. OBJECTIVE： To observe the effects of exercise preconditioning on muscle damage at different phases after eccentric exercise and changes of blood IL-6, CK and CK-MM. DESIGN, TIME AND SETTING： The randomized control animal experiment was carried out in the Animal Laboratory of Chengdu Sports University between 2006 and 2007. MATERIALS： Eighty female adult SD rats, weighing （231.3±12.44） g, were adopted. Eighty rats were randomly divided into without exercise preconditioning group （n=40） and exercise preconditioning group （n=40）. Each group was assigned into 5 subsets termed before exercise, immediately after exercise, 24, 48, 72 hours after exercise, with 8 rats in each subset. METHODS： Except before exercise subset, other rats in the without exercise preconditioning group were forced to do treadmill exercise （19-21 m/min, -16° incline, 90 minutes）. All rats of exercise preconditioning group were forced to do eccentric treadmill exercise for two weeks. After two weeks, treadmill test was made for rats except before exercise subset. MAIN OUTCOME MEASURES： Soleus muscle structure, blood IL-6, CK and CK-MM immediately, 24, 48, 72 hours after eccentric exercise. RESULTS： The soleus muscle was damaged after exercise, especially in without exercise preconditioning group at 24 48 hours after exercise. Blood IL-6 of without exercise preconditioning group increased significantly immediately after exercise and then gradually decreased, but again raised at 72 hours after exercise. In the exercise preconditioning group, blood IL-6 slightly reduced immediately after exercise and then gradually increased. Peak value appeared at 48 hours. After exercise, IL-6 of exercise preconditioning group was obviously lower than that of without exercise preconditioning group. Before exercise, serum CK and CK-MM of exercise preconditioning group were less than that of without exercise preconditioning group. After exercise, the CK and CK-MM were firstly raised and then reduced in two groups. Except 72 hours after exercise subset, the variation of CK and CK-MM of exercise preconditioning group was lower than that of without of exercise preconditioning group. CONCLUSION： Exercise preconditioning is redounded to lighten the ultrastructure injury of skeletal muscle induced by eccentric exercise and blood indices changes induced by exercise stress. The individual variation of CK and CK-MM is so tremendous that they fit the comparison of intrasubject variability.