Purpose: The purpose of this investigation was to examine the relationship between the expression of HSP60 and GRP75 and the oxidative potential of skeletal muscle as assessed by the citrate synthase activity following endurance training to sedentary controls.
Methods: Female Wistar rats were assigned to one of two groups: sedentary controls (N = 8) or endurance trained (N = 9). Endurance trained rats were run 60 min x d(-1) at 27 m x min(-1) up a 10% incline 6 d x wk(-1) for 8 wk on a motor-driven treadmill.
Results: Training produced a 47% increase in citrate synthase activity along with a 103% increase in the expression of HSP60 and a 105% increase in the expression of GRP75 in plantaris muscle. In addition, there was a significant correlation between the citrate synthase activity and expression of HSP60 found in plantaris muscle.
Conclusions: These findings are consistent with the hypothesis that the adaptive response to treadmill running may require elevations in the expression of HSP60 and GRP75 to support protein import and folding.