运动预适应对急性运动性损伤后心肌组织解耦联蛋白2表达及氧化应激水平的影响

Exercise preconditioning effect on uncoupling protein-2 expression and the oxidative stress level of myocardial tissue in exercise-induced myocardial damage

目的观察运动预适应对急性运动损伤后大鼠心肌组织解耦联蛋白2表达及氧化应激水平的影响,探讨运动预适应对急性运动性心肌损伤的保护作用。方法将30只健康成年雄性Wistar大鼠随机分为3组(每组各10只):安静对照组(C)、一次力竭运动组(E)、运动预适应+一次力竭组(EE)。通过一次性力竭游泳运动建立大鼠急性运动性损伤模型,EE组力竭运动前进行运动预适应训练,力竭运动时记录各组大鼠力竭时间,力竭运动后检测各组大鼠心肌线粒体内丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)水平;RT-PCR检测心肌组织解耦连蛋白2(UCP2)的m RNA水平,免疫组化法检测心肌组织UCP2蛋白表达。结果氧化应激水平:与C组比较,E、EE组心肌细胞线粒体SOD活性及GSH-Px活性均显著降低,SOD活性分别降低60.50%、28.64%(P均<0.01),GSH-Px活性分别降低51.23%、39.12%(P均<0.01),MDA浓度分别升高187.70%、155.66%(P均<0.01)。与E组比较,EE组心肌细胞线粒体SOD活性分别升高80.65%,GSH-Px活性升高24.83%;MDA浓度降低11.14%(P均<0.01)。UCP2表达水平:与C组比较,E组UCP2m RNA相对量及蛋白相对表达量均明显升高(P<0.01);与E组比较,EE组UCP2m RNA相对量及蛋白相对表达量均明显降低(P<0.01)。结论急性运动性损伤使心肌组织UCP2表达增多,并可提高氧化应激水平,运动预适应可减少UCP2表达并减轻氧化应激水平,对心肌组织具有保护作用。

Objective To investigate exercise preconditioning effect on uncoupling protein-2 expression and the oxidative stress level of myocardial tissue in exercise-induced myocardial damage, and the protective effect of exercise preconditioning on acute myocardial injury. Methods 30 healthy adult male Wistar rats were randomly divided into three groups (10 rats in each group): Quiet control group (C group), exhaustive exercise group (E group),exercise preconditioning and exhaustive exercise group (EE group). Sports injury model in rats was establish by a one-time acute exhaustive swimming exercise. EE group had exercise preconditioning training before acute exhaustive exercise. The exhaustion time was recorded in each group during exhaustive exercise. After exhaustion exercise testing, level of malondialdehyde (MDA) and superoxide dismutase (SOD) in myocyte mitochondria,glutathione peroxidase (GSH-Px), miRNA and protein of uncoupling protein-2 (UCP2) were measured. Results ①Oxidative stress: compared with that in C group, SOD activity in the E and EE group reduced by 60.50% and 28.64% respectively (all P<0.01); GSH-Px activity reduced by 51.23% and 39.12% respectively (all P<0.01); MDA concentration increases 187.70% and 155.66% respectively (all P<0.01). Compared with that in E group, SOD activity increased 80.65%, Gsh-Px activity increased 24.83%, and MDA concentration reduced by 11.14% in EE group (all P<0.01). ②UCP2 expression: compared with that in C group, mRNA and protein expression of relative quantity in E group were significantly increased (P<0.01), and compared with that in E group, mRNA and protein expression of relative quantity in EE group were significantly reduced (P<0.01). Conclusions Acute sports injury can increase the expression of UCP2, and can improve the level of oxidative stress. Exercise preconditioning can reduce UCP2 expression and oxidative stress level, it plays a protective role on myocardial tissue.