高住低练对大鼠骨骼肌PI3K/PKB/mTOR信号通路基因表达的影响

目的:探讨高住低练对大鼠骨骼肌PI3K/PKB/mTOR信号通路基因表达的影响。方法:40只8周龄SD大鼠适应训练后,随机分为低住安静组(LC)、低住低练组(LoLo)、高住安静组(HC)和高住低练组(HiLo)。高住组每天低氧暴露12 h(氧浓度13.6%,相当于海拔3500 m),低练组进行35 m/min、1 h/d、5 d/周、共4周的跑台训练。采用实时荧光定量PCR检测大鼠腓肠肌PI3K、PKB、mTOR mRNA表达,以双因素方差分析进行统计。结果:低氧和运动均显著提高大鼠骨骼肌PI3K和PKB mRNA表达(P<0.01),但低氧和运动无显著交互作用(P>0.05);运动显著提高大鼠骨骼肌mTOR mRNA表达(P<0.01),低氧却显著降低mTOR mRNA表达(P<0.01),且低氧和运动有交互作用,显著降低mTOR mRNA表达(P<0.01)。结论:低氧和运动促进PI3K和PKB基因表达,低氧抑制而运动促进mTOR基因表达;HiLo训练促进PI3K和PKB基因表达,却抑制mTOR基因表达。不同条件下PI3K/PKB/mTOR信号通路基因表达水平不一致。

Effects of Living-High Training-Low on the Gene Expression of PI3K/PKB/mTOR Signaling Pathway in Skeletal Muscle of Rats

Objective To evaluate the effects of living-high training-low on the gene expression of PI3K/PKB/mTOR signaling pathway in skeletal muscle of rats.Methods After adaptive training,40 8weeks-old male SD rats were divided into living-low quiet control group(LC),living-low training-low group(LoLo),living-high quiet control group(HC),living-high training-low group(HiLo).All living-high groups stayed in the environment with 13.6% oxygen concentration,about altitude of 3500 m,for 12 h/ day.All training groups underwent treadmill training with 35m/min for 1hour/day,5days/ week,4 weeks.The PI3K,PKB and mTOR mRNA genes expressions in skeletal muscle were measured by quantitative fluorescent PCR and tested by two-factor analysis of variance.Results(1) Hypoxia and training significantly increased PI3K and PKB mRNA expression(P < 0.01),and there was no significant interaction between hypoxia and training(P > 0.05).(2) Training significantly increased mTOR mRNA expression(P < 0.01),hypoxia significantly inhibited mTOR mRNA expression(P < 0.01),and the interaction between hypoxia and training also significantly inhibited mTOR mRNA expression(P < 0.01).Conclusions(1) Hypoxia and training can increase PI3K and PKB gene expression,and hypoxia inhibit but training increase mTOR gene expression.(2)HiLo training can increase PI3K and PKB gene expression but inhibit mTOR gene expression.The gene expression levels of PI3K/PKB/mTOR signaling pathway under different conditions are inconsistent.