耐力训练对大鼠骨骼肌Mfn2蛋白表达及线粒体功能的影响

目的:观察耐力训练对大鼠骨骼肌线粒体Mfn2蛋白表达及线粒体功能的影响,探讨耐力训练提高骨骼肌有氧代谢能力的线粒体机制。方法:20只雄性Wistar大鼠随机分为对照组(CN)和耐力训练组(ET),每组10只。ET组大鼠进行12周游泳耐力训练,CN组不训练正常饲养。12周后取大鼠腓肠肌,差速离心法提取线粒体,测定锰超氧化物歧化酶(MnSOD)活力、丙二醛(MDA)含量、线粒体呼吸功能、Mfn2基因和蛋白表达。结果:ET组大鼠腓肠肌线粒体MnSOD活性显著高于CN组(P<0.01),MDA含量低于CN组(P<0.05),态3呼吸和Mfn2蛋白表达水平显著高于CN组(P<0.05),呼吸控制比和Mfn2基因表达水平显著高于CN组(P<0.01),态4呼吸无明显变化。结论:12周游泳运动显著上调了Mfn2基因及蛋白表达,这可能是耐力训练提高骨骼肌有氧代谢能力的线粒体机制。

Endurance Training Affects Mfn2 Protein Expression and Mitochondrial Function in Skeletal Muscles of Rats

Objective To observe the effect of endurance training on Mfn2 protein expression and mitochondrial function.Methods Twenty male Wistar rats were randomly divided into sedentary control group(CN) and endurance training group(ET).Rats in ET were forced to swim for 12 weeks.The gastrocnemius muscle of rats were removed after 12 weeks,then the muscle mitochondria were rapidly extracted,and MDA,MnSOD,respiration function,and the expression of Mfn2 mRNA and protein were measured.Results Comparing with group NC,the activity of MnSOD increased significantly(P < 0.01),and the MDA content reduced significantly(P < 0.05) in group ET;the state 3 respiration and Mfn2 protein expression increased significantly(P < 0.05);the respiration control ratio and Mfn2 gene expression increased obviously(P < 0.01);and the state 4 respiration remained unchanged.Conclusion 12-week endurance training markedly increases the expression of mitochondrial Mfn2 mRNA and protein in the skeletal muscle,which seems to be related to the elevation of aerobic capacity in skeletal muscle.