力竭运动后大鼠心肌组织结构改变及不同时相PPARα表达的变化

Changes in Structure and PPARα of Myocardium at Different Time Courses Following Exhausted Exercise in Rats

目的:探讨力竭游泳运动后大鼠心肌组织结构的改变以及运动后不同时相过氧化体增殖物激活型受体α(PPARα)表达的变化。方法:90只成年健康雄性SD大鼠,分为安静对照组(n=10)和一次力竭游泳运动组(n=40)、2周反复力竭游泳运动组(n=40),后两组分别于力竭运动后即刻,6、12及24小时取材,应用HE染色和变色酸2R-亮绿染色技术观察大鼠心室肌组织结构和缺血缺氧改变,应用免疫荧光技术和图像分析方法测定各组大鼠心肌PPARα表达。结果:一次力竭运动后大鼠心肌HE染色可见形态结构异常,变色酸2R-亮绿染色可见心肌细胞浆存在点、片状红色缺血缺氧改变;一次力竭游泳运动后6小时右心室及室间隔PPARα蛋白表达显著低于对照组对应部位蛋白表达(P<0.01);反复力竭运动后即刻及24小时,室间隔PPARα蛋白表达均显著低于安静对照组(P<0.01)。结果提示,力竭运动后心肌PPARα表达水平与心肌受损程度有关,可能是运动性心肌微损伤发生的重要机制。

Objective The purpose of this study was to investigate the change in structure and PPARα （peroxisome proliferator-activated receptor alpha） content of myocardial tissue in rats at different time cases following exhausted exercise. Methods Ninety male SD rats were divided into sedentary control group （n=10）, single bout of exhausted swimming groups （n=40） and 14-day consecutive exhausted swimming groups （n=40）. Rats were killed at 0, 6, 12 and 24 hours after single bout of exhausted exercise and consecutive exhausted exercise. HE and C-2R dyeing techniques were used to observe the changes in ventricular structure and immunofluorescence technique and image-analysis method were employed to determine the changes in the content of PPARα in myocardium. Results Abnormal cardiac tissue structure was seen after single bout of exhausted exercise, and red dots or patches appeared in myocardium. The content of PPARα in right ventricle and interventricular septum decreased remarkably 6h after single bout of exhausted exercise as compared with that in control group （P 〈0.01 ）. The content of PPARα in interventricular septum decreased remarkably 0 and 24 h following consecutive exhausted exercises as compared with that in control group （P〈0.01）. Conclusion The content of PPARα in myocardial tissue relates to the degree of myocardial micro-injuries.