The Influence of Hypoxic Exercise on Upstreams of mTOR in Skeletal Muscle
|School||Beijing Sport University|
|Course||Human Movement Science|
|Keywords||hypoxic exercise PI3K PKB|
Aims:To study the effect and mechanism of hypoxic exercise on PKB/mTOR signal pathway in skeletal muscle,it tested the effect of hypocic exercise on Upstreams of PKB/mTOR signal pathway.Materials and methods:Adult male Sprague-Dawley rats(12 weeks old)were randomly divided into four groups:normoxia sedentary group(NS),normoxia Exercise group(NE),hypoxic sedentary group(HS),hypoxic exercise group (HE).The hypoxia circumstance was normal pressure hypoxia,oxygen concentration is 13.6%,which equivalented 3500m above sea level.HS and HE group constantly lived in hypoxia.Tested total protein、3-kinase(PI3K) and phosphorylation of protein kinase B of extensor digitorum longus(EDL) muscle on the 3rd day、7th day、14th day and 28th day.Results:(1) After 3 days,hypoxia inhibited total protein of PI3K significantly(p<0.05);After 7 days,exercise significantly promoted total protein of PI3K(P<0.01) while hypoxia inhibited it evidently(P<0.01) After 14 days,exercise significantly promoted total protein of PI3K(P<0.01)and phosphorylation of PKB(P<0.01) significantly, in the meanwhile,hypoxia inhibited both of them evidently;and the situation was the same as 14th day’ s after 28 days.(2) After 3 days,there was no difference between all groups about the total protein content.After 7 days,total protein content of NE group was higher than HS(P<0.05)and HE group(P<0.05).And after 14 days,HE group(P<0.01)and NE(P<0.05) group was higher than HS group.After 28 days,the total protein content of all the four groups had no significantly differences(P<0.05).Conclusions:Exercise promotes total protein of PI3K and phosphorylation of PKB significantly while hypoxia inhibits them evidently.Hypoxic exercise reduces the inhibition of hypoxia two both total protein of PI3K and phosphorylation of PKB,which means hypoxia represses muscle protein synthesis.