线粒体KATP开放剂二氮嗪对家兔心肌缺血—再灌注损伤的影响

Effects of mitochondrial ATP-sensitive potassium channel opener diazoxide on myocardial ischemia-reperfusion injury in rabbits

目的观察线粒体ATP敏感性钾通道(KATP)开放剂二氮嗪对家兔心肌缺血—再灌注(I/R)损伤的影响。方法将家兔随机分为A、B、C、D组各8只,分别于造模前30 min经耳缘静脉给予二氮嗪溶剂及1、3、5 mg/kg的二氮嗪;结扎家兔左冠状动脉前降支,进行30 min缺血和120 min的再灌注,建立心肌I/R损伤模型。在缺血和再灌注期,监测家兔的血压、心率、心电图和血清肌酸激酶(CK)的变化,用计算机图像分析测定心肌梗死面积。结果与A组比较,B、C组对家兔血压和心率无明显影响,D组可明显降低血压(P<0.01)。A组心肌梗死面积占左心室总面积的百分比为22.7%±9.2%,B、C、D组分别为19.1%±5.8%、12.7%±4.5%、11.8%±7.2%;与A组比较,C、D组梗死面积分别下降了44.1%、48.0%(P均<0.05)。与A组比较,C组CK于再灌注1、2 h分别下降16.3%、25.8%,D组分别下降31.8%、45.6%(P均<0.01)。结论线粒体KATP开放剂二氮嗪对家兔心肌I/R损伤具有保护作用。

Objective To investigate the effects of mitochondrial ATP-sensitive potassium channel opener diazoxide on myocardial ischemia-reperfusion （I/R） injury in rabbits. Methods The rabbits were randomly divided into A, B, C, D group with 8 each, respectively, in before making the model 30 rain through ear vein giving diazoxide solvent and 1, 3, 5 mg/kg diazoxide. The rabbit myocardial I/R injury model was established by ligating left anterior descending branch of cor- onary artery for 30 rain and reperfusing for 120 rain. During I/R period, the blood pressure, heart rates and electrocardio- grams were recorded and the serum creatine kinase （CK） levels were measured. The myocardial infarct sizes were calculat- ed by computer image analysis system. Results Compared with the A group, B and C groups had no significant effects on blood pressure and heart rates. But D group decreased the blood pressure remarkably （P 〈 0.01 ）. A, B, C, D groups of myocardial infarction size of the left ventricular area percentage were 22.7% ±9.2% , 19.1% ±5.8% , 12.7% ±4.5% and 11.8% ±7.2%. Myocardial infarction was lowered by 44.1% and 48.0% in C and D groups respectively compared to A group （P 〈0.05）. And C group decreased serum CK levels by 16.3% after 1 h of reperfusion and 25.8% after 2 h of reperfusion, while D group decreased by 31.8% and 45.6% respectively （ P 〈 0. 01 ）. Conclusion Mitochondrial ATP- sensitive potassium channel opener diazoxide has a myocardial protective effect on myocardial I/R injury in rabbits.