Qom University of Medical Sciences Journal

Background and Objectives: MicroRNA-1 (miR-1) is involved in various cellular processes, but the effect of endurance exercise on miR-1 expression in fast- and slow- twitch skeletal muscles has still remained unclear. The aim of this study was to evaluate the effect of one period of endurance exercise on miR-1 expression in slow- and fast-twitch skeletal muscles in male Wistar rats.

Methods: In this experimental study, 14 rats weighing 113±20 grams were housed under controlled conditions (animal laboratory of Tarbiat Modares university, 2014), and after familiarization (weight, 231±24 grams) were randomly divided into two groups of control (n=7) and experimental (n=7) groups. The experimental group did an endurance activity program (30m/min, 50 min/session, 6 session/week for 14 weeks) on a treadmill and 48 hours after the end of the last session, was anesthetized and sacrificed together with the control group. Then, the soleus and EDL muscles were removed. The expression level of miR-1 was measured using real-time RT-PCR. In the following, data were evaluated and compared using t-test.

Results: According to t-test results, The mean expression of miR-1 of soleus and EDL muscles in the experimental group, respectively, increased 2.77- and 4.48- fold, compared to the control group due to 14 weeks of endurance exercise, which these increases were significant at p<0.01 level.

Conclusion: The findings of this study showed that despite the difference in twitch type and muscle fiber properties, endurance exercise has the same effect on miR-1 expression in fast- and slow-twitch skeletal muscles.