胰岛素对糖尿病大鼠再灌注损伤性心肌的影响及可能机制

The Effection of Insulin in Diabetic Ischemia-reperfusion Myocardium and Signaling Pathway

目的观察胰岛素对糖尿病和非糖尿病大鼠再灌注损伤性心肌的影响并探讨其可能机制。方法复制实验性糖尿病大鼠模型,造模9周,结扎左冠状动脉前降支复制心肌缺血/再灌注模型。动物随机分为6组,糖尿病组和非糖尿病组分别给予生理盐水、胰岛素或胰岛素+渥曼青霉素。观察心肌血清酶学、心律失常评分及心肌磷酸化蛋白激酶b(p-Akt)和磷酸化Bad(p-Bad)表达。结果与非糖尿病对照组比较,胰岛素组可以使血清肌酸激酶(CK)和肌酸激酶同工酶(CK-MB)降低;胰岛素组心律失常评分降低;心肌组织p-Akt和p-Bad蛋白表达高于非糖尿病对照组,胰岛素的这种作用被渥曼青霉素取消。与糖尿病对照组比较,胰岛素组可以使血清CK和CK-MB降低;胰岛素组心律失常评分降低;心肌组织p-Akt和p-Bad蛋白表达增强,该变化可以被渥曼青霉素取消。胰岛素对糖尿病大鼠和非糖尿病大鼠的心肌再灌注损伤的影响的比较:糖尿病大鼠的血清CK和CK-MB高于非糖尿病大鼠;两者的心律失常评分比较无显著差异;非糖尿病胰岛素组心肌p-Akt表达高于糖尿病胰岛素组。结论胰岛素通过PI3K/Akt信号转导途径对于非糖尿病再灌注损伤心肌具有保护作用,胰岛素对于糖尿病再灌注损伤心肌同样具有保护作用,但保护作用效果弱于非糖尿病心肌。

Objective To evaluate the effect of insulin in diabetic ischemia-reperfusion myocardium and signaling pathway. Methods Following 9 weeks of streptozotocin-induced diabetes,SD rats were randomly divided into six groups:non-diabetic (control group,insulin group,wortmannin group),diabetic (control group,insulin group,wortmannin group).Ischemic/reperfusion was induced by occlusion of LAD coronary artery. We measured serum myocardial enzymes,observed susceptibility to reperfusion-induced ventricular arrhythmias,...