Effect of 20-Hydroxyecdysone on Proteolytic Regulation in Skeletal Muscle Atrophy.

BACKGROUND/AIM 20-Hydroxyecdystone (20E) is an ecdysteroid hormone which controls molting and reproduction in arthropods. 20E also produces a variety of effects in vertebrates, including enhancing protein synthesis and skeletal muscle regeneration. The effect of 20E on disuse muscle atrophy has not been reported to date. This study examined the proteolytic regulation of 20E in tenotomized rat slow soleus and fast plantaris muscles. MATERIALS AND METHODS Male Wistar rats were randomly divided into three groups: sedentary control (CON), tenotomy without 20E treatment (TEN), and tenotomy with treatment of 5 mg/kg BW of 20E (TEN+20E). The TEN+20E group was administered 20E via subcutaneous injection to the right thigh for 7 days after tenotomy. RESULTS 20E treatment tended to attenuate disuse muscle atrophy and reduced ubiquitination only in soleus muscle. CONCLUSION 20E treatment alleviates skeletal muscle atrophy partially mediated by ubiquitinate pathway, dependent on the muscle phenotype.