The effect of endurance training on miR-133 expression and SRF gene in slow and fast twitch skeletal muscles of wistar rats

MicroRNA-133 and SRF is involved in various cellular processes, but the effect of endurance training on gene expression of this factors in fast and slow twitch muscles has still remained unclear. The aim of this study was to evaluate the effect of endurance training on miR-133 and SRF gene expression in fast and slow twitch muscles in male Wistar rats. In this study, 14 rats weighing 113±20 grams (5 weeks age) were housed under controlled conditions, after familiarization protecols they were randomly assigned into control (7 rats) and experimental (7 rats) groups. The experimental group performed 14 weeks, 6 session per week endurance training program (that gradually reached to 60 min and 30 m / min) on treadmill and 48 hours after the end of the last session, both groups were sacrificed. The soleus and EDL muscles were removed. The gene expression level of miR-133 and SRF were measured using real- time RT-PCR. Data were analysd by sample t-test. After 14 weeks of endurance training the gene expression of miR-133 of fast twitch muscle (EDL) in experimental group significantly decreased (p=0.001) than control group .But the miR-133 gene expression of slow twitch muscle (soleus) in experimental group was significantly increased (p=0.001) than control group. Also miR-133 gene expression of EDL of experimental group was significantly decresed (p=0.001) than soleus muscle of the same group; the rate of SRF gene expression of EDL of experimental group increased significantly (p=0.009) but it did not effect on SRF gene expression in soleus. Endurance training induced differences in gene expression of miR-133 and SRF gene consistent to specification of fast and slow twitch muscles.