A potential indicator of denervated muscle atrophy: the ratio of myostatin to follistatin in peripheral blood.

Myostatin is a secreted negative regulator of muscle mass, and follistatin antagonizes the function of several members of the TGF-b family, including myostatin. Previously, myostatin expression was found to be closely associated with atrophy of the gastrocnemius muscle, showing a linear correlation, after sciatic nerve injury. In this study, we investigated the possibility of myostatin being an indicator of denervated muscle atrophy. ELISA was used to detect the concentration of myostatin and follistatin in sera collected from individual rats at different times after sciatic nerve crush. A strong correlation was shown between the expression level of secreted myostatin in circulation and the wet weight ratio of the gastrocnemius muscle. The ratio of follistatin/myostatin could be used to monitor the progress of target muscle atrophy and recovery. Our study provides a potential serological test to detect denervated muscle atrophy for clinical purposes.