间歇游泳训练对大鼠心肌缺血再灌注损伤的保护作用

Protective effect of interval swimming exercises on the myocardium ischemia-reperfusion injury in rats

目的探讨间歇游泳训练对缺血再灌注损伤大鼠心肌损伤的保护作用。方法将60只大鼠随机分为间歇运动组、假手术组和模型组,每组20只。心肌缺血再灌注前,间歇运动组大鼠进行间歇游泳训练,假手术组和模型组大鼠不运动。连续训练8周后,间歇运动组和模型组大鼠结扎左冠状动脉前降支,使大鼠心肌缺血30 min,松开结扎线再灌注60 min;假手术组大鼠开胸穿线但不结扎。采用实时定量聚合酶链反应和Western blot技术检测大鼠心肌组织c-fos、Bcl-2 mRNA和蛋白的表达;应用原位细胞凋亡法测定心肌细胞凋亡情况;利用酶联免疫吸附实验检测大鼠心肌组织内超氧化物歧化酶(SOD)、丙二醛(MDA)活性的变化。结果与假手术组比较,模型组大鼠c-fos mRNA与蛋白的表达显著升高,而Bcl-2 mRNA与蛋白的表达显著降低(P<0.01);与模型组比较,间歇运动组大鼠c-fos mRNA与蛋白的表达显著降低,而Bcl-2 mRNA与蛋白的表达显著升高(P<0.01)。模型组大鼠心肌细胞凋亡指数与假手术组比较显著增加,间歇运动组大鼠心肌细胞凋亡指数与模型组比较明显降低(P<0.01)。与假手术组比较,模型组大鼠心肌组织总SOD活性降低,MDA活性显著增高(P<0.01);与模型组比较,间歇运动组大鼠心肌组织总SOD活性增高,MDA活性显著降低(P<0.01)。结论间歇游泳训练能够明显降低c-fos的表达,增强Bcl-2的表达,提高心肌细胞SOD活性,减少MDA生成,从而对心肌组织发挥良好的保护作用。

Objective To explore the protective effect of interval swimming exercises on the myocardium ischemiareperfusion injury rats. Methods Sixty rats were randomly divided into interval exercises group,sham operation group and model group,with 20 rats in each group. The rats in interval exercises group were conducted high intensity interval swimming exercises for eight weeks,the other two groups were not given any exercises training. After training for eight weeks,myocardial ischemia-reperfusion injury in interval exercises group and model group were induced by the occlusion of left anterior descending branch of coronary artery in vivo. After 30 min ischemia and 60 min reperfusion,while the rats in sham operation group were not given occlusion of left anterior descending branch of coronary artery in vivo. Real-time polymerase chain reaction and Western blot methods were used to examine the mRNA and protein expression of c-fos and Bcl-2; the changes of cardiac cell apoptosis were measured by TDT-mediated d UTP nick end labeling technique; the levels of superoxide dismutase（ SOD） and malondialdehyde（ MDA） were examined by enzyme linked immunosorbent assay. Results The mRNA and protein expressions of c-fos in model group increased more obviously than those of sham operation group,but the mRNA and protein expressions of Bcl-2 in model group decreased more obviously than those of sham operation group（ P〈0. 01）; the mRNA and protein expressions of cfos in interval exercises group decreased more obviously than those of model group,but the mRNA and protein expressions of Bcl-2 in interval exercises group were increased more obviously than those of model group（ P〈0. 01）. The myocardial apoptotic index in model group was higher than that in sham operation group,in interval exercises group it was lower than that in model group（ P〈0. 01）. The activity level of SOD in the cardiac tissue of model group was significantly lower than that of sham operation group,and the activity level of MDA in the cardiac tissue of the model group was higher than that of sham operation group（ P〈0. 01）. The activity level of SOD in the cardiac tissue of interval exercises group was significantly higher than that in model group,and the activity level of MDA in the cardiac tissue of interval exercises group was lower than that of model group（ P〈0. 01）. Conclusion Interval swimming exercises plays a protective role by decreasing the expresion of cfos,increasing the expression of Bcl-2 and the activity levels of SOD,decreasing the activity levels of MDA.