The study of timing series response of microRNA-1 expression to resistance exercise in slow and fast muscles of Wistar male rats

Introduction and Purpose:

microRNAs (miRs) are involved in cellular different processes and inhibit gene expression. One of these miRs is microRNA-1 (miR-1) which is special in muscles-tissue and the rate of it decreases with muscular hypertrophy. Regarded to difference of slow and fast muscles to resistance exercise، the purpose of this study was to evaluate the effect resistance exercise (RE) on miR-1 expression in fast and slow skeletal muscles of Wistar male rats.

The subjects of this Fundamental study were15 rats that were randomly assigned to RE (n=10) or control groups (n=5); the RE group performed one session RE (climbing a 1-meter–long ladder with 4 set، 5rep)، then 3 and 6 hours after RE with control group were anaesthetized and sacrificed، the soleus and Extensor digitorum longus (EDL) muscles -slow and fast twitch skeletal muscle respectively- were removed. The miR-1 expression rate was determined by Real time RT-PCR method. To analysis of dates the one sample t test and independent t test were used.

The results showed that in response to RE، the expression of EDL miR-1 was significantly decreased 99 and 73 percent at 3 (P<. 0001) and 6 hours (P<. 0001) after exercise respectively. While the expression of soleus muscle miR-1 decreased by 40 percent (P<. 323) and then increased 224 percent (P<. 196) at 3 and 6 hours after RE respectively but these changes were not significant. Discussion and

one session RE induce decrease in miR-1 in EDL muscle، it is probably a sign of proliferation in EDL muscle.