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

GONG Xue; LI Xiao-yan

doi:10.3969/j.issn.1674-4055.2017.01.09

Abstract：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.Results①Oxidative stress: compared with that in C group, SOD activity in the E and EE group reduced by 60.50% and 28.64% respectively (allP<0.01); GSH-Px activity reduced by 51.23% and 39.12% respectively (allP<0.01); MDA concentration increases 187.70% and 155.66% respectively (allP<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 (allP<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.