Effect of Spinal Nerve Ligation after Endurance Training on the Gene Expression of MST1 and MAFbx in Plantaris Muscle of Male Wistar Rats

Reduction of muscle mass occurs in some models of muscle atrophy during mechanical unloading status and MST1 and MAFbx genes are believed to have a role. In the present study, the effect of reduced physical activity in the form of spinal nerve ligation (SNL) after a period of endurance training (ET) on the expression of MST1 and MAFbx genes were examined in the rat plantaris muscle.

In this experimental study, 16 rats were randomly divided into two groups: control-spinal nerve ligation (Sham+SNL) and endurance training-spinal nerve ligation (ET+SNL). Training program continued for six weeks, four sessions a week with moderate intensity (70-60% of VO2max). To create the SNL model, the rats were first anesthetized with pentobarbitol sodium and then their fifth lumbar spinal nerve was tightly tied. The duration of the SNL protocol was four weeks. After the last day of ligation, the plantaris muscle was extracted. Real-Time PCR was used to measure the mRNA expression of the MST1 and MAFbx.

The expression of MST1 gene showed no significant increase in ET+SNL group compared with Sham+SNL group (P>0.05). But, significant increase was seen in MAFbx gene expression in ET+SNL group compared with Sham+SNL group (P<0.05).

The study showed that reduced activity in the form of SNL after endurance training can lead to destructive effects on the muscular system and symptoms of muscle atrophy could be seen.