肌电图用于评价缺血预处理减轻大鼠骨骼肌缺血再灌注损伤的研究

Evaluation of electromyography on ischemic preconditioning and reperfusion injury in skeletal muscle of rats

目的:探讨针极肌电图(EMG)对缺血预处理(IPC)减轻大鼠骨骼肌再灌注损伤的应用价值。方法:将75只健康6周龄SD鼠随机分成Ⅰ组(正常值组),Ⅱ组(实验组或缺血预处理组),Ⅲ组(对照组或未经预处理组),每组25只。Ⅱ组为加压止血带捆扎大鼠后肢缺血再灌注损伤的动物模型,连续观察患侧胫前肌损伤即刻及第3、7、14、28天的针极肌电图改变、组织病理变化、后肢神经功能评分。结果:Ⅱ组肌电图在损伤后第3天出现单个运动单位电位(MUP),第14天与Ⅰ组比较MUP时限增宽、波幅升高、多相电位增多(P<0.01),第28天所有参数与Ⅰ组比较差异无显著性(P>0.05);而Ⅲ组在第7天出现单个MUP,第28天静息状态仍显示+1处正锐波、纤颤电位。病理变化在损伤后第3、7天最明显。后肢神经功能评分:损伤后第7天Ⅱ组有3只达到4级,损伤后第14天Ⅱ组有3只达到5级,第28天全部达到5级,与Ⅲ组比较有显著性差异(P<0.01)。结论:针极肌电图的动态观察是评价缺血预处理减轻骨骼肌再灌注损伤的客观指标之一。

Objective： To study the value of needle electromyography（EMG） on ischemia preconditioning（IPC） on lsclaemm and reperfusion injury in skeletal muscle of rats. Method： Seventy-five healthy six-week old SD rats were randomly divided into group I （normal value,n=25）. group 1I （experiment or IPC,n=25） and group III （control or no IPC,n=25）. The model of ischemia and reperfu- sion injury was made by blocking the blood flow of hind limb with a pneumatic tourniquet in order to ob- serve the changes of needle EMG（on injury instantly and the 3th,7th, 14th,28th day later） and histopathology of tibialis anterior muscle and the nervous function scores of hind limb. Result： Electromyography of group 1I showed single motor unit potential（MUP） on the 3rd day of ischemia and reperfusion injury.Compared with group [ ,on the 14th day,the changes of duration,amplitude,multiphase wave of MUP increased（P〈0.01）,on the 28th day all parameter hadn＇t significant difference（P〉0.05）;and those of group m showed single MUP on the 7th day, electromyography still showed ＋1 spontaneous activity.The most marked histopathology change occurred on the 3rd day of ischemia and reperfusion injury. The nervous function scores： grouplI had 3 rats with grade 4 on the 7th day and had 3 rats with grade 5 on the 14th day and had all with grade 5 on the 28th day, Conclusion： The dynamic observation compared with group lll indicated with needle EMG was one of significant difference（P〈O.O 1）. the objective and sensitive methods to evaluate ischemia and reperfusion injury after IPC of skeletal muscle of rats.