目的 探讨电针延缓大鼠失神经骨骼肌萎缩的可能机制。方法 雄性Sprague-Dawley大鼠18只随机分为假手术组(n=6)、模型组(n=6)和电针组(n=6)。后两组钳夹伤右侧坐骨神经制备失神经骨骼肌萎缩模型。造模后第2天,电针组电针右侧足三里穴和环跳穴,共2周。取双侧腓肠肌称重,计算腓肠肌湿重比;HE染色测量肌纤维横截面积和直径;Western blotting检测大鼠骨骼肌中哺乳动物雷帕霉素靶蛋白(mTOR)、磷酸化mTOR (p-mTOR)、70KD核糖体蛋白S6激酶(p70S6K)和磷酸化p70S6K (p-p70S6K)蛋白表达;实时定量聚合酶链反应检测大鼠骨骼肌中mTOR、p70S6K基因表达。结果 与假手术组相比,模型组和电针组腓肠肌湿重比、肌纤维横截面积及直径显著下降(P<0.001),电针组明显高于模型组(P<0.01)。与假手术组相比,模型组右侧腓肠肌mTOR、p-mTOR、p70S6K和p-p70S6K蛋白表达升高(P<0.01);电针组高于模型组(P<0.05)。与假手术组相比,模型组右侧腓肠肌mTOR、p70S6K基因表达升高(P<0.05);电针组高于模型组(P<0.05)。结论 电针可延缓失神经骨骼肌萎缩,可能与激活mTOR/p70S6K信号通路,影响骨骼肌蛋白合成有关。
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.
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