中文摘要：

目的改进心肌缺血再灌注模型的制备,研究大鼠心肌缺血再灌注的心电图特点和损伤心肌超微结构改变,确定判断模型成功的心电图标准。方法制备幼年雄性SD大鼠心肌缺血再灌注模型,气管切开,开胸,结扎时将一硅胶管与冠状动脉一起结扎,结扎30min后再灌注;观测记录心电图改变,制作常规电镜切片,观察超微结构改变。结果造模成功率90%;心电图：QRS波群增高是判断结扎完全的标准;心肌酶水平升高显著;超微结构破坏明显。结论该方法有效建立心肌缺血再灌注模型,提出心电图判断标准;心肌超微结构损害明显。

英文摘要：

Objective To improve the methods of making myocardial ischemia - reperfusion model and observe the changes of electrocardiogram and ultrastructure of myocardium in rats. Methods The chest of young male SD rats through the fourth intercostal space was opened, and the left coronary artery was tied with a silicagel tube, after 30 minutes, untied to perfuse. Changes of electrocardiogram were observed and recorded. After reperfusion,the levels of AST,LDH ,and CK - MB were measured and the tissue samples of the infarct areas were examined by transmission electronic microscope. Results The 90 percent of total rats were made myocardial ischemia reperfusion model successfully. In myocardial ischemia reperfusion rats：the QRS wave of myocardial ischemia -reperfusion rats was much higher than that of control group;the level of cardiac enzymes increased ; myocardial and vascular endothelial cells ultrastructure was damaged seriously. Conclusions The improvement of modus operandi is right. Ischemia reperfusion can cause evident damage of myocardial and vascular endothelial cells uhrastructure in rats, and damage of myocardial cells is more severe than vascular endothelial cells.