电损伤兔骨骼肌细胞内钙分布变化

目的:探讨电损伤骨骼肌细胞内钙离子分布变化及其意义.方法:36只兔随机均分为实验组和对照组,实验组制作成兔胫前单束肌高压电损伤精细模型.分别在电击后2、8、24、48、72 h和5 d每组随机抽取3只兔,取A区段肌组织标本,采用电镜细胞化学胞内Ca2 原位沉淀法检测亚细胞Ca2 分布,同时行HE染色观察其形态学变化.结果:电击后胞浆、线粒体内出现钙颗粒并渐增多,而肌浆网钙颗粒则减少、消失,这种Ca2 紊乱在伤后24～48 h达到高峰.之后钙颗粒开始减少,但至伤后第5天仍存在.对照组钙颗粒仅见于肌浆网.HE染色显示肌组织呈进行性坏死,这种病理改变与亚细胞Ca2 分布变化相一致.结论:骨骼肌高压电损伤后发生亚细胞Ca2 分布紊乱,胞浆和线粒体存在持续钙超载.它可能是电损伤骨骼肌进行性坏死的重要原因之一.

Investigation of Intracellular Calcium Distribution in Electricity-injuried Skeletal Muscles

Objective:To investigate the changes of intracellular calcium distribution in electricity-injuried skeletal muscles.Methods: Thirty-six rabbits were divided randomly into Control Group and Experimental Group.A subtle model of high voltage electric injury to a single-bundle anterior tibial muscle in rabbits was prepared and used in this experiment.Muscle samples obtained at different time spots postinjury were studied for subcellular calcium distribution using potassium pyroantimonate electron microscope cytochemistry and changes in pathology on HE stain.Results: The calcium granules were visualized in cytoplasm and mitochondria at 2h postinjury,and increased gradually,while decreasing and vanishing away in sarcoplasm reticulum.This disturbance peaked at 24-48h postinjury,declined afterwards,but remained detectable up to day 5.Calcium granules in Control Group appeared only in sarcoplasm reticulum.Muscle fibers showed progressive necrosis in consistency with subcellular calcium distribution changes.Conclusion: The persistent subcellular calcium imbalance and overload in cytoplasm and mitochondria may be one of the major causes of the progressive muscular necrosis.