有氧耐力训练对大鼠骨骼肌线粒体功能及PI3K-Akt蛋白的表达影响

The influence of the aerobic endurance training on the skeletal muscular mitochondria function and PI3K-Akt protein expression

目的:观察有氧耐力训练大鼠骨骼肌线粒体磷脂酰肌醇3-激酶-蛋白激酶B(PI3K-Akt)信号通路的表达情况。方法:将36只大鼠随机分为3组(n=12):对照组、有氧耐力训练组和一次性力竭组。分组干预结束后,检测各组大鼠骨骼肌线粒体膜电位(MMP)水平、琥珀酸脱氢酶(SDH)和细胞色素C氧化酶(COX)活性,利用Western blot法测定组织中磷脂酰肌醇3-激酶(PI3K)和蛋白激酶B(PKB或Akt)的磷酸化水平。结果:与对照组相比,一次性力竭组大鼠MMP、SDH和COX活性水平、磷酸化PI3K和磷酸化Akt蛋白水平明显降低(P<0.05);而有氧耐力训练组大鼠上述指标均显著高于一次性力竭组(P<0.05),与对照组比无明显差异。结论:有氧耐力训练对大鼠骨骼肌线粒体具有保护作用,其机制可能与活化PI3K-Akt信号通路有关。

Objective： To determine the role of phosphatidylinositol 3-kinase - protein kinase B （PI3K-Akt） signaling pathway in the protective effect of aerobic endurance training on the skeletal muscular mitochondria. Methods： Thirty-six rats were randomly divided into three groups（ n = 12） ： control group, aerobic endurance training group and one-time exhaustive group. After the intervention, the quadriceps femoris muscle sample was obtained to detect the mitochondrial membrane potential（MMP）, the activities of succinate dehydrogenase（SDH） and cytochrome coxidase（COX）, and the protein levels of p-PI3K and p-Akt. Results： Compared with the control group, the levels of mitochondrial membrane potential, the activities of succinate dehydrogenase and cytochrome coxidase, and the protein levels of p-PI3K and p-Akt were all significantly decreased in the one-time exhaustive group（ P 〈 0.05）. However, all the above was partially reversed in the endurance training group（ P 〈 0.05）,and there was no obvious difference with the control group（ P 〉 0.05）. Conclusion： Aerobic endurance training plays an important role in the protective effect on the skeletal muscular mitochondria, the mechanism may be related to activation PI3K-Akt signaling pathway.