Background and Aim: Endurance activity can affect function and also factors involved in skeletal muscle transcription. The aim of this study was to investigate the effects of an endurance activity program on the Sox6 gene and miR-499 expression in fast and slow twitch skeletal muscles in male Wistar rats.

Materials and Methods: we kept 14 rats under controlled conditions and divided them randomly into control and experimental groups. The experimental group performed an endurance activity program for 14 weeks, (6 days/wk, 1 hour/day) by using a treadmill. 48 hours after the end of the last session they were anesthetized and sacrificed. The soleus and extensor digitorum longus muscles were removed. Real time RT-PCR method was used to determine the expression levels of miR-499 and Sox6<span dir="RTL" style="letter-spacing: -0.3pt; font-family: " b="" nazanin";="" font-size:="" 12pt;="" mso-ascii-font-family:="" "times="" new="" roman";="" mso-hansi-font-family:="" roman";"=""> genes. Data analysis was performed by t-test.

Results: The results showed, that sox6 gene expression in EDL muscles increased significantly in the experimental group compared to that in the control group (p<0.004). But, in the experimental group sox6 gene expression in soleus muscle decreased significantly compared to the control group (p<0.002). Expression of miR-499 in the soleus muscle increased significantly due to endurance activity (p<0.015).

Conclusion: Considering different changes of sox6 and miR-499 expression in the skeletal muscles after the same endurance activity, it seems that these two factors create the conditions in the skeletal muscle tissue, which despite the long-term endurance activities these muscles can maintain appropriate ratios of fast and slow-twitch fibers

Key words: sox6 gene, Endurance activity, miR-499

Received: Jan 30, 2016      Accepted: Jan 9, 2017