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

Abstract

Exercise training induces significant changes in the performance of skeletal muscle. 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. 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. 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. These results indicate that both moderate and high intensity exercise increase the relative SERCA2a expression in the gastrocnemius.