摘要
Abstract
Objective To explore the influence of diabetes on myocardial ischemia reperfusion (I/R) in ischemic preconditioning (IPC) rats and its underlying mechanism.Methods Thirty diabetic and thirty non-diabetic SD rats were chosen and respectively divided into three groups (n= 10) randomly.Sham operation group (Sham group): after thoracotomy, a thread was passed under the coronary but without ligation, and 155 min later the experiment was ended.Ischemia reperfusion group (I/R group): after thoracotomy, a thread was passed under coronary artery, wait for 35 min, and then the ligature was lightened for 30 min to produce ischemia and then followed by 90min of reperfusion.Ischemic preconditioning group (IPC group): after thoracotomy, a collar was made by threading method, balanced for 35 min, and then the rats were subjected to 5 min of ischemia and 5 min of reperfusion for 3 cycles, followed by 30 min of ischemia and 90min of reperfusion.The contents of serum creatine kinase (CK), lactate dehydrogenase (LDH), myocardial malonyldialdehyde (MDA),and superoxide dismutase (SOD) were determined, and the extent of myocardial infarction and myocardial glucose uptake rate were also assessed before ischemia and after the end of the experiment in all groups.Results In non-diabetic rats, the CK, LDH, and MDA contents were significantly higher in I/R and IPC group than those in Sham group (P＜0.05 or 0.01), and were significantly higher in I/R group than in IPC group (P＜0.05 or 0.01), while the SOD was significantly lower in I/R and IPC group than in Sham group (P＜0.01), and was significantly lower in I/R group than in IPC group (P＜0.01).The area of myocardial infarction was lower, while the myocardial glucose uptake rate was higher in IPC group than in I/R group (P＜0.05).In diabetic rats, no obvious difference of the above index was found between IPC and I/R group (P＞0.05).Conclusion Diabetes may counteract the protective effect of ischemic preconditioning on myocardial ischemia reperfusion injury in rats; the mechanism may be related to the insulin resistance of myocardium.关键词
糖尿病/缺血预处理,心肌/心肌再灌注损伤/胰岛素抗药性Key words
diabetes mellitus/ ischemic preconditioning, myocardial/ myocardial reperfusion injury/ insulin resistance分类
医药卫生
