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

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(P0.01).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(P0.05).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(P0.01).Conclusion Mitochondrial ATP-sensitive potassium channel opener diazoxide has a myocardial protective effect on myocardial I/R injury in rabbits.