Effects Of Diazoxide On Acute Myocardial Infarction In Old Rabbits

Objective: To investigate the cardioprotective effect of Diazoxide , an ATP-sensitive potassium channel opener, on acute myocardial infarction in old rabbit.Methods: 36 old New Zealand rabbits were random divided into four groups: control group (n=9) , simplicity coronary artery ligation group (n=9) , diazoxide with 7. 5mg/kg group (n=9) , diazoxide with 15mg/kg group (n=9) The models of acute myocardial infarction (AMI) in old rabbit were established by ligating the left anterior descending (LAD) coronary artery. The rabbits of diazoxide group were respectively given diazoxide (7. 5mg/kg . d and 15mg/kg . d) by oral for 4 days;In the fifth day the rabbits of 3 groups , exception the control group, were opened chest and ligating the left anterior descending (LAD) coronary artery. The levels of myocardial enzyme, Lactate Dehydrogenase (LDH), Creatin-Kinase (CK) Muscle-Brain (CK-MB) were measured 6h later. The change of electrocardiographic , blood pressure , rhythm of the heart and the infarction size of myocardial infarction was monitored as well. Histological examinations were performed.Results: Compared with the controls ,the levels of serum LDH,CK,CK-MB in old rabbits with opened chest and ligating the left anterior descending(LAD) coronary artery were significantly increased, the section ST and T-wave were obviously redounded, there were extremely remarkable difference(P<0.01).