Differential effects of exercise training on skeletal muscle SERCA gene expression.

INTRODUCTION: Exercise training induces significant changes in the performance of skeletal muscle.
PURPOSE: To determine whether changes in the gene expression of rat hind-limb muscle sarcoplasmic reticulum Ca2+ -ATPase isoforms (SERCA1a and SERCA2a) in response to either moderate- or high-intensity exercise training underlie the functional remodeling.
METHODS: SERCA1a and SERCA2a isoform mRNA expression was determined in predominantly fast-twitch, gastrocnemius muscle and predominantly slow-twitch, soleus muscle with northern analysis. SERCA mRNA was normalized by the 18S rRNA measured in the same sample.
RESULTS: Significant increases in the gastrocnemius SERCA2a mRNA expression were observed after both moderate- and high-intensity training. No significant change in SERCA1a expression was found under any conditions.
CONCLUSION: These results indicate that both moderate and high intensity exercise increase the relative SERCA2a expression in the gastrocnemius.