糖尿病大鼠心肌梗死后易发心力衰竭的机制

目的研究STZ诱导的血糖不加控制的糖尿病大鼠急性心肌梗死（AMI）后易发心力衰竭（HF）的机制。方法217只SD大鼠随机分组，糖尿病组经腹腔内注射链脲酶素（STZ，65mg／kg）诱导糖尿病，10周后所有AMI组结扎冠状动脉左前降支建立AMI模型。确定AMI前和AMI后1天，7天，14天，28天，56天做为实验观察时间点，观察大鼠的生存率，心肌超微结构的变化，进行心脏超声检测、心肌纤维化测定及左心肥厚的评估。结果结扎左冠状动脉前降支后，糖尿病大鼠的死亡率、左心功能恶化及左室重构的速度均较非糖尿病大鼠显著。在早期阶段，糖尿病与非糖尿病大鼠心肌纤维化相似，而1月后却出现显著差别。结论糖尿病加速了STZ诱导的糖尿病大鼠AMI后心脏重构的进展。

The mechanism of the susceptibility to Heart Failure in Streptozotocin-induced Diabetic Rat Model with Acute Myocardial Infarction

AIM To explore the mechanism of the susceptibility to heart failure in streptozotocin-in- duced diabetic rat model for 10 weeks with acute myocardial infarction(AMI)in vivo.Methods 217 SD rats were randomized into four groups.Diabetes were induced by a single intraperitoneal injection of strepto- zotocin(STZ,65mg/kg),and 10 weeks later after the induction,AMI models were made with the ligation of left anterior descending coronary artery.Then we determined the time course of diabetic effects on the devel- opment of heart failure in rats before and 1d,7d,14d,28d,and 56d after AMI,to observe the survival rate of the rats and ultrastructure change of myocardium,perform transthoracic echocardiography,quantify the ex- tent of the myocardial fibrosis,and assess the cardiac hypertrophy.Results After the ligation of left anteri- or descending coronary artery,diabetic rats have higher mortality,worse LV function and accelerated Left Ventricular(LV)remodeling compared with non-diabetic ones.Myocardial fibrosis in both diabetic and non- diabetic rats subjected to AMI is similar in the early phase,while it is quite different after 1 month. Conclusion Diabetes mellitus may accelerate the progression of post-infarction cardiac remodeling in Strep- tozotocin-induced Poorly controlled Diabetic Rat Model.