Effect of Reduced Physical Activity on Murf-1 and Atrogin-1 Gene Expression in Soleus Muscle of Wistar Rats Following Endurance, Resistance and Combined Training

Understanding the involved mechanisms in muscle atrophy can help develop new treatment methods for atrophic conditions. Skeletal muscle atrophy via biochemical and transcriptional pathways can increase the expression of some muscle atrophy related genes. The present study aims to assess the effect of reduced physical activity by the spinal nerve ligation (SNL) after a period of resistance, endurance and combined exercises on the expression of MuRF-1 and Atrogin-1 genes in male rats.

In this experimental study, 30 male Wistar rats were randomly divided into four groups: Control+SNL, combined exercise+SNL, endurance exercise+SNL, and resistance training+SNL. The exercises were performed for six weeks. After this period, the protocol of reduced physical activity by the SNL was implemented for four weeks. At the end, soleus muscle was isolated and the expression levels of MuRF-1 and Atrogin-1 genes were measured by real-time polymerase chain reaction technique. To examine the gene expression differences between the groups, analysis of variance and Tukey’s post hoc test were used. The significant level was set at 0.05.

The results showed that the expression of MuRF-1 gene in the combined exercise+SNL and resistance training+SNL groups was significantly lower than in the control group (P<0.05). The Atrogin-1 gene expression was significantly reduced only in the combined exercise+SNL group compared to the control group (P<0.05).

It seems that the rats with resistance training are more resistant to SNL-induced atrophy than the group with endurance exercise.