The Effects Of AMPK On Skeletal Muscle PPARα Expression In Hypoxic Endurance Training

Objective:We aim to discuss the effect of AMPK on PPAR a when given wide type mice, AMPK a2over-expression mice and AMPK a2knock-out mice endurance training, hypoxic stimulation and hypoxic endurance training for4weeks.Methods:C57BL/6JWild-type (WT) mice, AMPK a2over-expression (OE) mice and AMPKα2knockout (KO) mice were divided into normal control group, normal endurance training group, hypoxic control group and hypoxic endurance training group respectively. All the endurance training groups are trained treadmill running at0degree and the speed of12m/min for lh/day,6days a week and it lasts for4weeks. While all the hypoxia groups are given intermittent hypoxia(8hour a day, about4500m above’ sea level) for4weeks.12-16hours after the last training, skeletal muscle was collected. AMPKα-Thr172phosphorylation and nuclear PPAR a are tested by Western blotting and PPAR a mRNA expression tested by Real Time-PCR.Results:(1) After4weeks’intermittent hypoxia and hypoxia endurance training, the phosphorylation of AMPKα-Thr172in all the three different groups has advanced.(2) The expression of nuclear PPAR a protein in all the three different groups has increased after4week hypoxia.(3) Compared to WT mice, hypoxic endurance training can significantly increase the AMPKα phosphorylation and nuclear PPAR a expression in OE mice, while decrease that in the KO mice. This indicates that nuclear PPAR a level has an closely relation with AMPKα-Thr172phosphorylation.Conclusions:(1) After4weeks’intermittent hypoxia and hypoxia endurance training, the phosphorylation of AMPKα-Thr172in all the three different groups has advanced, and that proved AMPK had a significant role in maintaining the energy metabolism.(2) The expression of nuclear PPAR a protein in all the WT mice has increased after4week hypoxia, and showed that hypoxia endurance training can increase the activity of PPAR.(3) Compared to WT mice, the expression of nuclear PPARα protein in OE mice had significantly increased, and there was a decrease of the expression of nuclear PPARα protein in KO mice, after4weeks’hypoxia endurance training. That proved that the expression of nuclear PPARα protein can be increased by AMPKα under the influence of hypoxia endurance training.