The Changes in Contractile Protein Degradation and 26S Proteasome Activity of Skeletal Muscle in Rat after an Acute Exercise / 中国运动医学杂志

ABSTRACT

Objective To explore the effects of an acute exercise on the contractile protein degradation and 26S proteasome activity in skeletal muscle.Methods Thirty-six male Sprague-Dawley rats were randomly divided into 6 groups,each group consisted of 6 rats.They were killed respectively at rest,immediately after half an hour of exercise(running on the treadmill at 25m/min,5% grade),and 1 hour,2h and 6h after one hour exercise.The 3-methylhistidine(3-MH)content,26S proteasome activity and C2 subunit mRNA expression in rat gastrocnemius muscle were detected.Resuits(1)3-MH content increased immediately and 6 hours after exercise,and reached its peak level immediately after half an hour of exercise(P<0.01).(2)26S proteasome activity increased immediately after half an hour of exercise and 6 hours after exercise(P<0.05).(3)Expression of 26S proteasome C2 subunit mRNA Was lower than baseline during and after exercise,but increased sharply 6 hours after exercise(P<0.01).Conclusion The increase in 26S proteasome activity regulated by subunits gene after exercise could enhance skeletal muscle contractile protein degradation