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 min 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 coronary artery for 30 min and reperfusing for 120 min. During I/R period, the blood pressure, heart rates and electrocardiograms were recorded and the serum creatine kinase (CK) levels were measured. The myocardial infarct sizes were calculated 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.%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、2h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.
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