关键词: 失神经肌萎缩, 电针, 蛋白合成, 哺乳动物雷帕霉素靶蛋白, 70KD核糖体蛋白S6激酶, 大鼠

Abstract: Objective To explore the effects and mechanism of electroacupuncture (EA) on denervation-induced atrophy in rats. Methods A total of 18 male Sprague-Dawley rats were divided into sham group (n=6), model group (n=6) and EA group (n=6). The latter two groups were clamped right sciatic nerve to establish atrophy model of skeletal muscle. On the second day after modeling, EA group accepted electroacupuncture on right Zusanli (ST36) and Huantiao (GB30) for two weeks. Their gastrocnemius muscles were obtained after intervention, and the wet weight ratio of the gastrocnemius muscles was calculated. The cross-sectional area (CSA) and diameter of muscle fibers were measured after HE staining. The protein expression of mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR), 70-KD ribosomal protein S6 kinase (p70S6K) and phosphorylated p70S6k (p-p70S6k) was tested with Western blotting. The gene expression of mTOR and p70S6K was detected with real-time quantitative polymerase chain reaction. Results Compared with the sham group, the wet weight ratio of the gastrocnemius muscle, CSA and diameter of the muscle fibers decreased in the model group and EA group (P<0.001), which were more in EA group than in the model group (P<0.01); the protein expression of mTOR, p-mTOR, p70S6K and p-p70S6K increased in the model group (P<0.01), and increased more in EA group (P<0.05); the gene expression of mTOR and p70S6K increased in the model group (P<0.05) , and increased more in EA group (P<0.05).Conclusion Electroacupuncture delays the atrophy of denervated skeletal muscles, which may relate to activation of mTOR/p70S6K signal pathway to impact synthesis of skeletal muscle proteins.

Key words: denervated skeletal muscle atrophy, electroacupuncture, protein synthesis, mammalian target of rapamycin, 70-KD ribosomal protein S6 kinase, rats