四周高住低训对大鼠骨骼肌p70^(S6K)的影响

The Effects of Four Weeks Living High-Training Low on p70^(S6K) of Skeletal Muscle in Rats

目的:探讨低氧运动对大鼠骨骼肌蛋白量及p70S6K的影响。方法:SD大鼠分为四组:常氧安静组、低氧安静组、常氧训练组、高住低训组。常氧安静组在常氧环境下安静生活;低氧安静组在氧浓度13.6%低氧舱内安静生活;常氧训练组和高住低训组进行4周的跑台运动,每天训练1 h,每周训练6 d。高住低训组晚上在氧浓度13.6%低氧舱内低氧暴露。结果:28 d后,与对照组比较,高住低训组骨骼肌总蛋白浓度显著下降(p<0.01),p70S6K蛋白表达显著增加(p<0.05),p70S6K(Thr389)磷酸化水平显著降低(p<0.01);常氧训练组p70S6K蛋白表达显著增加(p<0.05);低氧安静组p70S6K(Thr389)磷酸化水平显著降低(p<0.01)。结论:1)高住低训抑制了骨骼肌蛋白合成及p70S6K(Thr389)磷酸化,这也提示机体可能通过调节mTOR/p70S6K细胞信号转导通路来调节骨骼肌蛋白代谢;2)耐力运动提高了骨骼肌p70S6K蛋白的表达。

Objective： To explore the influence of hypoxic exercise on skeletal muscle protein and p70^S6K in rats.Methods： SD rats are divided into four groups： control group,hypoxic group,normal exercise group and living high-training low（HiLo） group.Control group lives in normal environment quietly.Hypoxic group was traded with 13.6% oxygen concentration all the day,and live quietly.The other two groups take four weeks exercises,1hour/day,and 6 days/week.And HiLo group was traded with 13.6% oxygen concentration during night.Results： After 28 days,compared with control group,HiLo group＇s total protein concentration in rat skeletal muscle decreased significantly（p0.01）,but p70^S6K protein expression increased significantly（p0.05）,and p70^S6K（Thr389） phosphorylation also decreased significantly（p0.01）;Normal exercise group＇s p70^S6K protein expression increased significantly（p0.05）;Hypoxic group＇s p70^S6K（Thr389） phosphorylation decreased significantly（p0.01）.Conclusions：1） In our study,HiLo suppresses skeletal muscle protein synthesis and p70^S6K（Thr389） phosphorylation,which suggests that it may adjust the skeletal protein synthesis by adjusting p70^S6K/mTOR signal transduction pathways.2） Endurance sports promote skeletal p70^S6K protein expression.