失神经支配骨骼肌超微结构及Na,K-ATP酶、Ca-ATP酶变化

目的　探讨失神经支配骨骼肌超微结构及酶组织化学变化。方法　选用SD大鼠 ,切断胫神经建立失神经支配腓肠肌实验模型。观察骨骼肌超微结构变化 ,测定肌肉Na,K ATP酶及Ca ATP酶含量。结果　肌肉超微结构变化主要表现为线粒体与肌质网扩张、空泡化直至消失 ,细胞核仁自 4周开始略扩大 ,12周后缩小 ;Na ,K ATP酶含量 4周内下降不明显 ,6周后呈进行性下降 ;Ca ATP酶含量 2周时下降近 1/ 3 ,以后一直维持在正常值 60 %～ 70 %。结论　Na ,K ATP酶活性可作为反映肌肉萎缩程度可靠酶组织化学指标 ;Ca ATP酶活性变化规律说明失神经支配后肌肉收缩的生理基础长期存在。

Change of Ultrastructure and Na,K-ATPase,Ca-ATPase on Denervated Skeletal Muscle

Purpose To study the change of ultrastructure and enzyme histochemistry of denervated skeletal muscle. Methods 42 Spray?Dawley rats were used and the models of denervated gastrocnemius muscle were established by cutting off the tibial nerve.The activities of Na,K?ATPase and Ca?ATPase were measured.The muscle cell ultrastructure was observed. Results The degeneration of mitochondria and sarcoplasmic reticulum were accelerated along with the denervated time.Na,K?ATPase activity did not reduced significantly within 4 weeks,but reduced progressively after 6 weeks,Ca?ATPase activity reduced one?third of normal value at 2 weeks,but it remained 60-70 per cent afterwards. Conclusions Na,K?TPase acti vity was a reliable enzymic histochemistry index.The physiologic basis of constriction existed in longer time after denervation.