Abstract: Objective To observe effects and mechanism of electroacupuncture (EA) on denervated skeletal muscle atrophy. Methods Forty-nine male Sprague-Dawley rats were randomly divided into normal group (group A, n=7), natural recovery group (group B, n=21) and EA group (group C, n=21). The groups B and C, established the model of denervated skeletal muscle atrophy by transecting the sciatic nerve of rats, were divided into subgroups of 7 days, 14 days, 21 days postoperation, seven in each subgroup. Electroacupuncture was given to the group C at Zusanli (ST36) and Chengshan (BL57) once a day since 24 hours after modeling. The muscle wet weight ratio of the affected gastrocnemius was determined. Cross-sectional area and fiber diameter of the gastrocnemius were measured with HE staining. The expression of insulin-like growth factor-1 (IGF-1), Myostatin and proliferating cell nuclear antigen (PCNA) protein and gene in the gastrocnemius were detected with Western blotting and RT-PCR. Results The wet weight ratio, cross-sectional area and fiber diameter were less in the groups B and C than in the group A (P<0.001), and they were more in the group C than in the group B (P<0.001). Compared with the group B, the protein and gene of IGF-1, PCNA increased in the group C (P<0.05), while the Myostatin decreased (P<0.05). Conclusion Electroacupuncture can increase the expression of IGF-1 and decrease the expression of Myostatin, to promote the proliferation of satellite cell, which may relate with the prevention of denervated skeletal muscle atrophy.

Key words: denervation, muscle atrophy, electroacupuncture, insulin-like growth factor-1, Myostatin, proliferating cell nuclear antigen, satellite cell, rats