不同强度运动对大鼠骨骼肌AMPK/PGC-1α信号通路的影响

Effects of Different Intensity Exercise on AMPK/PGC-1α Signaling Pathway in Skeletal Muscle of Rats

目的:通过12周不同强度运动干预,从大鼠骨骼肌AMPK/PGC-1α通路角度,研究运动改善心肺耐力的生物学机制。方法:40只雄性Wistar大鼠随机分为安静组、小强度运动组(50%6)VO2max)、中强度运动组(65%6)VO2max)、大强度运动组(80%6)VO2max),每组10只。经3天适应性训练后测试大鼠最大摄氧量。运动组大鼠每天训练1 h,每周5天,共12周。训练期间每隔2周测试一次最大摄氧量。经过12周训练,于最后一次运动后48 h宰杀所有大鼠,取比目鱼肌(右侧)。采用RT-q PCR法测定AMPK、PGC-1α基因表达,采用Western blot法测定AMPK、PGC-1α、磷酸化AMPK蛋白表达。结果:65%6)VO2max组和80%6)VO2max组最大摄氧量提升较快,而50%6)VO2max组在干预后期才出现明显升高;12周运动干预后,50%6)VO2max组和80%6)VO2max组PGC-1αm RNA表达显著高于安静组和中强度组(P<0.01),安静组和80%6)VO2max组AMPK m RNA表达显著低于中强度组(P<0.05,P<0.01);运动组PGC-1α蛋白表达高于安静组,其中65%6)VO2max组相比安静组具有显著性差异(P<0.05);AMPK蛋白表达组间相比没有显著差异,但中强度运动组和大强度运动组磷酸化AMPK相比安静组有所增加,大强度运动组增加幅度更大,显著高于安静组和小强度运动组(P<0.05)。结论:随着运动强度的增加,骨骼肌磷酸化AMPK表达增加;运动强度越大不代表PGC-1α蛋白表达会越高;中强度运动对AMPK/PGC-1α信号通路的影响可能更有益于心肺耐力的提升。

Objective ： To investigate the biological mechanism of exercise to improve cardiorespiratory fitness （CRF） through exercise based on 12 weeks of exercise intervention with different intensities on the skeletal nmsele AMPK/PGC - 1 a palhway in rats. Methods ： 40 male Wistar rats were randomly divided into four groups with 10 in each group, i.e. sedentary group, low intensity group （50% VO2max） , moderate intensity group （65% VO2 max） , and high intensity group （80% VO2 max）. All rats were measured for the VO2 max after three days adaptive training. After that, the rats in the exercise groups were trained for 12 weeks, 5 day a week, and lhour per day. They were tested for VO2 max every two weeks during the training period. All rats were sacririced 48 hours after the last exercise and their soleus （right） was isolated. The AMPK and PGC - 1α gene expression were detected by RT - qPCR while the AMPK, PGC - 1α, and phosphorylated AMPK protein expression by Western Blot. Results： The VO2 nlax in 65% VO2 nlax group and 80% VO2 max group increased rapidly, while the VO2 max in 50% VO2 max group increased significantly in the late stage of intervention. After 12 weeks of intervention, the PGC -1α mRNA expression in 50% VO2 max group and 80% VO2 max group were significantly higher than that in sedentary group and moderate intensity group （ P 〈 0.01 ） , the AMPK mRNA expression in sedentary group and 80% VO2 max group were significantly lower than that in 65% VO2 max group （P 〈 0.05, P 〈 0.01 ）. The PGC - 1α protein expression in the exercise groups was higher than that in sedentary group, with only the PGC -1α protein expression in 65 % VO2 max group being significantly higher than that in sedentary group （ P 〈 0. 05 ）. There was no significant difference in AMPK protein expression among the groups, while the phosphorylated AMPK protein expression in moderate intensity group and high intensity group increased as compared with sedentary group. The increase in 80% VO2 max group was greater, significantly higher than that in sedentary group and low intensity group （ P 〈 0.05）. Conclusions ： Higher exercise intensity does not mean that PGC - 1α protein expression will increase correspondingly. The effect of moderate intensity exercise on the AMPK/PGC -1α signaling pathway may be more beneficial for CRF.