运动预适应对急性运动性损伤后心肌组织氧化应激及凋亡的影响

目的:观察运动预适应对急性运动性损伤后大鼠心肌组织氧化应激及凋亡的影响,探讨运动预适应对急性运动性心肌损伤的保护作用。方法:30只健康成年雄性Wistar大鼠随机分为3组(每组10只):安静对照组(C组)、急性力竭运动组(E组)、预适应急性力竭运动组(EP组)。C组不进行任何运动训练,直接处死;E组与EP组通过力竭游泳运动建立大鼠急性运动性心肌损伤模型,并于力竭后立即处死,EP组于力竭运动前进行运动预适应训练。检测各组心肌线粒体超氧化物歧化酶(SOD)活性、丙二醛(MDA)水平和谷胱甘肽过氧化物酶(GSH-Px)活性;RT-PCR及免疫组织化学法检测心肌组织凋亡相关蛋白基因Bax和Bcl-2的表达水平,原位缺口末端标记法(TUNEL法)检测大鼠心肌细胞凋亡率。结果:(1)氧化应激水平:与C组相比,E组和EP组心肌细胞SOD及GSH-Px活性均显著降低,且E组降低更多;MDA水平均升高,且E组升高更多(P均0.01)。(2)凋亡水平:与C组相比,E组和EP组Bax mRNA表达水平明显升高,Bcl-2 mRNA表达水平明显降低,且与E组相比,EP组变化程度较小(P均0.01);TUNEL检测结果显示,与C组相比,E组和EP组大鼠心肌细胞凋亡率明显升高,但EP组较E组明显降低(P均0.01)。结论:运动预适应可减轻力竭运动后大鼠心肌组织氧化应激水平,减少心肌细胞凋亡,对心肌组织具有保护作用。

Effect of exercise preconditioning on oxidative stress and apoptosis of myocardial tissue after acute sports injury

Objective:To observe the effect of exercise preconditioning on oxidative stress and apoptosis of myocardial tissue after acute sports injury, and explore the protective effect of exercise preconditioning on acute myocardial injury in sports.Methods:Thirty healthy adult male Wistar rats were randomly divided into three groups (10 in each group): quiet control group (C), exhaustive exercise group (E), exercise preconditioning and exhaustive exercise group (EP).Acute sports injury model was established by one-time acute exhaustive swimming exercise and the rats were killed immediately after exhaustive exercise.The group EP had the exercise preconditioning training before acute exhaustive exercise.The concentration of MDA, the activty of SOD and GSH-Px in mitochondria of myocardial cell were detected.RT-PCR and immunohistochemical method were used to detect the expression of apoptosis related gene BAX and BCL-2 in myocardial tissue.TUNEL method was used to detect the apoptosis rate of rat myocardial cell.Results:(1)Oxidative stress: The SOD and GSH-px activity of group E and EP significantly reduced compared with group C, and the group E reduced more (all P<0.01).The MDA concentration of group E and EP increased, and the E group increased more (all P<0.01).(2) Apoptosis: Compared with group C, the expression of BAX mRNA in group E and EP was significantly higher, while the expression of BCL-2 mRNA was significantly lower, in addition the group EP changed less (all P<0.01).TUNEL test results showed that the apoptosis rates of myocardial cell in group E and EP significantly increased compared with group C, but the group EP significantly decreased compared with group E (all P<0.01).Conclusion:Exercise preconditioning can reduce the oxidative stress level and myocardial cell apoptosis of rats after exhaustion exercise, which plays a protective role in myocardial tissue.