The Effect of Intensive Endurance Activity on Myocyte Enhancer Factor 2C Gene Expression of Slow and Fast Twitch Muscles in Male Wistar Rats: An Experimental Study

Myocyte enhancer factor 2c activates the genes of the slow-twitch muscle, the muscle which plays role in endurance activity. Therefore, the aim of this study was to evaluate the effect of a program of intensive endurance activity on MEF2c gene expression in fast and slow twitch skeletal muscles in wistar rats. In this experimental study, 14 males wistar rats (231 ± 24 grams), after familiarization were randomly assigned into control (n=7) and experimental (n=7) groups. The experimental group performed an endurance activity program (30 m/min, 50 min, 6 sessions per week for 14 weeks) on motorized treadmill, and 48 hours after the end of the last session of endurance activity were anesthetized and sacrificed then the soleus (slow-twitch) and extensor digitorum longus (fast-twitch) muscles were removed. Real time PCR was used to determine expression levels of MEF2c gene and the data were analyzed by independent t-test. The MEF2c gene expression in fast-twitch muscle of the experimental group was significantly more compared to the control group (p=0.001), and the expression of MEF2c gene in soleus muscle of the experimental group significantly increased after 14 weeks endurance activity compared to the control group (p=0.022). Intensive endurance activity increases MEF2c gene expression in slow and fast twitch skeletal muscle which this change in gene expression probably provides grounds to obtain endurance characteristics in slow and fast twitch skeletal muscles.