不同时长高强度间歇训练与中等强度持续运动对大鼠骨骼肌AMPK、PGC-1α表达量及最大摄氧量的影响

摘要

目的:探讨不同时长高强度间歇训练(high intensity interval training,HILT)与中等强度持续运动对骨骼肌氧化能力相关因子AMPK和PGC-1α表达量及最大摄氧量(VO2max)的影响,为制定有效的运动健身负荷提供参考.方法:120只6周龄SPF级雄性Wistar大鼠按体重随机分为安静对照组、中等强度持续运动组与HIIT组三组,每组各40只.安静对照组大鼠不运动,中等强度运动组以60％～70％VO2max强度进行持续训练,HIIT组以50％VO2max、70％VO2max、90％VO2max的强度交替训练.跑台训练每周5天,每天50分钟.每周日上午8:00～9:00进行体重测量.每组大鼠分别在训练2、4、6、10周后取比目鱼肌,每组每次随机选取10只大鼠,取材前均进行VO2max测试.随后采用Western Blot检测比目鱼肌中AMPK、PGC-1α蛋白的表达情况.结果:(1)大鼠运动周数和运动方式分别对大鼠体重具有非常显著的影响且具有非常显著的交互作用(P＜0.01);(2)相同训练周期下,10周HIIT组大鼠骨骼肌PGC-1α含量显著高于安静对照组(P＜0.05),VO2max显著高于安静对照组和中等强度运动组;(3)相同训练方式下,10周HIIT组大鼠VO2max与0、2、4、6周时相比均有显著增高(P＜0.05),中等强度持续运动组训练至第4周时骨骼肌AMPK蛋白表达量显著高于第2周和第6周,同时显著高于2周安静组(基准值)(P＜0.05),HIIT组第2至第10周期间PGC-1 α蛋白表达量均显著高于2周安静对照组(基准值)(P＜0.05);(4)10周内HIIT组PGC-1α蛋白表达量与最大摄氧量时序性变化趋势具有显著相关关系(P＜0.05).结论:(1)10周HIIT可以有效提高大鼠骨骼肌AMPK和PGC-1α的蛋白表达量以及最大摄氧量;(2)10周HIIT相对于传统中等强度持续有氧运动对提高骨骼肌氧化能力和机体心肺耐力更为快速有效.%Objective To explore the effects of different weeks of high intensity interval training (HIIT) and moderate intensity aerobic exercise on maximal oxygen uptake (VO2max) and the expression of the skeletal muscle oxidative capacity related factor AMP-activated protein kinase (AMPK) and peroxisome proliferators γactivated receptor coativator-1-α (PGC-1α),so as to provide the basis for the choice of effective load intensity.Methods One hundred and twenty 6-week-old SPF male Wistar rats were equally randomized into 3 groups according to their body weight:a sedentary control group (not receiving any exercise),a moderate-intensity exercise group (undergoing 50-min continuous running at an intensity of 60％-70％ VO2max) and a HIIT group (conducting 3-min running at 90％ VO2max interspersed with 3-min recovery periods at 50％ VO2max and repeating that process 6 times,with a 7-min warm-up and cool-down period at 70％ VO2max).All rats except those in the control group exercised five days a week and 50min per day.All rats were measured their weight at 8:00-9:00am every Sunday.Soleus was taken from ten randomly chosen rats of each group at 2nd,4th,6th and 10th week after the onset of the intervention.The VO2max test was done before taking muscles.Western blotting was used to detect the protein expression of AMPK and PGC-1α.Results (1) Both the exercise duration and mode had a significant impact on rats' body weight,and they had interaction with each other (P＜0.01).(2) The average PGC-1α expression in the skeletal muscle of 10-week HIIT group were significantly higher than those in the control group (P＜0.05),and the average VO2max at the same time was also significantly higher than the other two groups.(3) In the HIIT group,the average VO2max at the 10th week was significantly higher than that at the 2nd,4th and 6th week (P＜ 0.05).The average protein expression of AMPK in the skeletal muscle at the 4th week in the moderate-intensity exercise group was significantly higher than that at the 2nd and 6th week of the same group,and that at the 2nd week of the control group (P＜0.05).The average protein expression of PGC-1α in the HIIT group from the 2nd to the 10th week was significantly higher than the control group at the 2nd week (P＜0.05).(4)The protein expression of PGC-1α was significantly correlated with temporal variation of VO2max in the HIIT group (P＜0.05).Conclusion Ten-week HIIT can effectively promote the expression of AMPK and PGC-1α in skeletal muscles and the maximal oxygen uptake.It plays a more quick and effective role in improving oxidant capacity and cardiorespiratory endurance of skeletal muscles than traditional moderate-intensity exercises.