摘要
目的:研究2周低氧、低氧训练对AMPKα2三种不同基因状态鼠骨骼肌GLUT4表达及肌糖原含量的影响,以探讨低氧、低氧训练对小鼠骨骼肌GLUT4基因和蛋白表达的影响及可能机制。方法:野生小鼠和AMPKα2高表达转基因小鼠,AMPKα2基因敲除小鼠各30只,分别随即分为常氧对照组、低氧暴露组和低氧训练组。低氧暴露组小鼠于低氧房(模拟海拔4000m高度,氧浓度约为12.3%)低氧暴露2周,低氧训练组小鼠2周低氧暴露同时每天于同浓度低氧房中跑台运动1h,跑台速度12m/min。最后一次跑台训练后12h取材,测定小鼠骨骼肌GLUT4基因和蛋白表达、AMPKα2蛋白表达以及肌糖原水平。结果:1)野生鼠,2周低氧暴露以及2周低氧训练后GLUT4基因和蛋白含量,与常氧对照组相比均显著增加,且低氧训练组小鼠比低氧暴露组增加更为显著。2)AMPKα2的高表达小鼠与野生鼠相比,2周低氧暴露后GLUT4蛋白和基因含量并没有显著差异,而经过2周低氧训练后,AMPKα2的高表达鼠骨骼肌GLUT4蛋白和基因表达量比野生鼠增加更为显著。3)AMPKα2基因敲除小鼠骨骼肌GLUT4表达量2周低氧训练后与野生鼠相比无显著差异,而2周低氧暴露后显著低于野生鼠。结论:1)低氧及低氧训练均能引起骨骼肌GLUT4表达的增多,且低氧和训练引起的GLUT4表达的增多可能有叠加效应。2)在低氧+训练双重刺激下,AMPKα2的高表达参与了调节GLUT4基因和蛋白表达的增加。3)低氧暴露引起的GLUT4基因和蛋白表达的增加至少部分是依赖AMPKα2调节,而在低氧+训练双重刺激下,机体还可以募集其他的信号通路完全代偿AMPKα2对GLUT4表达的调节作用。
Purpose：To investigate the effects of two weeks hypoxia treatment and hypoxia training on GLUT4 expression in mouse skeletal muscle and explore whether AMPK was involved in regulation of muscle GLUT4 expression induced by hypoxia treatment and hypoxia training.Methods：Expressions of GLUT4 mRNA and protein as well as the content of glycogen in quadriceps femoris muscle from control, hypoxia treatment and hypoxia training groups of AMPKα2 over-expression （OE）, AMPKα2 knockout （KO）, and corresponding wild-type （WT） mice was measured.Mice of hypoxia treatment groups were living in rooms with enriched nitrogen, simulating an altitude of 4,000 meter, in normobaric hypoxia （O2 12.3%） for two weeks.Hypoxia training groups were also living in this room but had an additional 60 min treadmill running training in normobaric hypoxia at the speed of 12m/min every day.Results：1）The content of GLUT4 mRNA and protein both increased significantly after two weeks hypoxia treatment as well as two weeks hypoxia training.2）The expression of muscle GLUT4 protein in AMPKα2-OE mice was significant higher than that in WT mice after two weeks hypoxia training.3）The expression of GLUT4 and the content of muscle glycogen in α2-KO mice,which were same with those in WT mice after two weeks hypoxia training,were significantly lower than that in WT mice after two weeks hypoxia treatment.Conclusion：1）The effectiveness of the hypoxia treatment and hypoxia training on expression of GLUT4 was validated in the present study.2）The AMPKα2-OE was involved in up-regulation of muscle GLUT4 expression induced by hypoxia training.3）The present study demonstrated that the cellular mechanism underlying the up-regulation of GLUT4 expression by hypoxia treatment and hypoxia training must be at least partly different,while hypoxia treatment induced GLUT4 expression in mouse skeletal muscle through a mechanism that was partially mediated by AMPKα2,pathways other than AMPKα2 were important in mediating the hypoxia trainin
出处
《体育科学》
CSSCI
北大核心
2010年第5期41-48,共8页
China Sport Science
基金
北京市自然科学基金(5072031)
卫生部人类疾病比较医学重点实验室开放课题基金(ZDS200804)
