缺血预适应对糖尿病大鼠心肌梗死的影响

The effect of myocardial ischemic preconditioning on myocardial infarction in diabetic rats.

目的 :通过建立大鼠缺血预适应 (IP)模型 ,探讨IP对缺血 再灌注 (I/P)糖尿病大鼠心肌梗死的影响。方法 :向SD大鼠腹腔内注射链脲素 (6 0mg/kg)制造糖尿病大鼠模型。2天后 ,随机时刻测定血糖 ,将血糖≥ 13 9mmol/L定为糖尿病大鼠 2 0只 ,另外 2 0只血糖正常鼠为非糖尿病鼠。 2周后 ,麻醉大鼠 ,结扎和放松冠脉左前降支 (LAD)复制IP和I/P模型。将 40只大鼠分为IP糖尿病大鼠组 (DIP组 )、IP非糖尿病大鼠组 (NDIP组 )、非IP糖尿病大鼠组(DNIP组 )和非IP非糖尿病大鼠组 (NDNIP组 )各 10只。记录Ⅱ导联心电图。取心脏切片染色 ,计算心肌缺血范围和心肌梗死范围。结果 :各组间心肌缺血范围无显著差异 (P >0 0 5 )。DIP组心肌梗死范围较DNIP组明显减小 (P <0 0 1)。DNIP组室性心律失常增多 ,尤其室颤较其他各组显著增多 (P <0 0 1)。结论 :缺血预适应可以减轻糖尿病大鼠随后较长时间缺血 再灌注对心肌的严重损害 ,能减少心肌梗死范围和降低室颤的发生率。

Objective:To study the effects of the myocardial ischemic preconditioning(IP) on diabetic rat myocardial infarction by using rat ischemic reperfusion(I/P)model.Methods:The diabetic rat model was established intraperitoneal by streptozotocin injection(60mg/kg).After two days,the diabetic rats were divided according to blood sugar≥13 9mmol/L.After two weeks,the myocardial IP and I/P models were established by anesthetizing SD rats,ligating and releasing left anterior descending coronary artery.Forty SD rats were divided into four groups everly(diabetic rats IP group,DIP group;non diabetic rats IP group,NDIP group;diabetic rats non IP group,DNIP group;non diabetic rats non IP group,NDNIP group). ECGs lead Ⅱ were recorded continuously.The sizes of the myocardial ischemia and infarction were calculated.Results:The sizes of the myocardial ischemia were not different in various groups(P>0 05).The size of myocardial infarction in DIP groups was significantly smaller than that of DNIP group(P<0 01). Ventricular arrhythmias were increased in DNIP group,especially,ventricular fibrillation was significantly increased compared with other groups(P<0 01).Conclusion: Myocardial ischemic preconditioning could markedly reduce infarct sizes and ventricular fibrillation arrhythmias induced by ischemic reperfusion injury.