消瘿强肌汤对甲亢肌病骨骼肌运动终板的影响

Effect of Xiaoyingqiangjitang on the Motor End-plate of Skeletal Muscle in Hyperthyroid Myopathy

目的观察消瘿强肌汤对甲亢肌病大鼠骨骼肌运动终板超微结构的影响和乙酰胆碱酯酶活性的变化。方法36只健康雌性Wistar大鼠随机分为正常对照组(n=6)和模型组、中药治疗组、生理盐水对照组(均n=10),后3组腹腔注射甲状腺激素钠盐制作甲亢肌病模型,中药治疗组注射甲状腺激素后再灌服中药方剂消瘿强肌汤。光、电镜观察运动终板乙酰胆碱酯酶活性变化及运动终板超微结构的变化。结果模型组各型骨骼肌纤维运动终板乙酰胆碱脂酶活性均较正常对照组明显减弱,酶反应产物减少,分布不均,超微结构显示突触间隙电子密度高低不等,接头褶减少、变短,轴突终末内线粒体空泡化。中药治疗组运动终板乙酰胆碱酯酶活性明显恢复,接头褶结构、轴突终末内部分线粒体结构恢复正常。结论消瘿强肌汤可恢复甲亢肌病骨骼肌运动终板乙酰胆碱酯酶活性,改善骨骼肌运动终板超微结构。

Objective To observe the effect of Xiaoyingqiangjitang on the ultrastructure of motor end-plate of skeletal muscle in rats with hyperthyroid myopathy, and changes of acetylcholin esterase （AchE）. Methods The 36 healthy female Wistar rats were randomly divided into the normal control group （n= 6）, and model group, Chinese medicine treated group and saline control group （all n= 10）. All animals in the model group, Chinese medicine treated group and saline control group were treated with group given L-thyroxine intraperitoneal injection for 42 days to establish the animal model of hyperthyroid myopathy. The animals of the Chinese medicine treated group were treated with Xiaoyngqiangjitang for 30 days after L-thyroxine intraperitoneal injection. The enzyme ac- tivity of Ache and ultrastructure of motor end-plate were observed by light and electron microscopes. Results The enzyme activity and content in the group of hyperthyroid myopathy was decreased, the reaction products of AchE located in synapse became weaker and distributed heterogeneously, the iunction infolding of motor end-plate became smaller and shorter, the mitochondria in axon ter- minal became vacuolated. After given Chinese medicine, the enzyme activity and content increased, the junction folding, the mito- chondria showed normal ultrastructural appearance. Conclusion Xiaoyingqiangjitang can improve the function of skeletal muscle in hy- perthyroid myopathy by recovering the enzyme activity of AchE and ultrastructures of motor end-plate.