有氧运动对大鼠骨骼肌和血清microRNA-24和eNOS表达的影响

摘要

为探讨不同持续时间有氧训练对大鼠骨骼肌和血清中NO生成的影响及分子机制,随机把40只雄性SD大鼠分为4组(n=10):对照组、2周训练组、4周训练组和6周训练组,采用Gries's法测定股四头肌和血清NO含量,采用试剂盒测定总一氧化氮合酶(NOS)活性和诱导型一氧化氮合酶(iNOS)活性,采用实时定量PCR测定各型一氧化氮合酶及microRNA-24的表达.结果表明:与对照组相比,随着运动时间的增加,实验组骨骼肌和血清中NO含量明显增加,差异显著(P<0.05,P<0.01),在训练第4周达到最大,并且不随训练时间延长而增加;有氧训练后,股四头肌microRNA-24的表达水平显著升高;有氧训练引起cNOS的活性和eNOS mRNA的表达均显著升高(P<0.05,P<0.01),而iNOS的变化不显著.可以认为:有氧运动可通过上调microRNA-24的水平,上调eNOS的表达和活性,从而增加NO生成量.这可能是有氧运动调节eNOS表达的机制之一.%To elucidate the effects of aerobic exercise on the production of NO and the mechanism that regulate the expression of NOS,40 male SD rats were separated into control group and training group for 2 weeks, training group for 4 weeks,training group for 6 weeks,n=10. The levels of NO in quadriceps and serum were detected by Gries's method,and the activity of NOS in quadriceps was detected by nitrix oxide synthase detection kit,the expression of different types of NOs and microRNA-24 was detected by RT-qPCR. Results: To compare with control group,NO production was elevated significantly in both quadriceps and serum in aerobic exercise groups(p<0.05,p<0.01)and approach the peak point after 4 weeke exercise,and maintained in the same levels even suatained exercise for longer time. Both total NOS and cNOS activity were enhanced in quadriceps,but aerobic exercise had no effects on the activity of iNOS. Aerobic exercise significantly increased the expression of eNOS and microRNA-24(p<0.05,p<0.01). To sum up,aerobic exercise elevates the production of NO by upregulating the expression of eNOS. In addition,aerobic exercise down-regualtes the expression of microRNA-24,which maybe the reason why aerobic exercise can enhance the activity of eNOS.