Ⅱ型糖尿病大鼠心梗后非梗死区心室重构的研究

目的:对比观察糖尿病(DM)大鼠心肌梗死(MI)后非梗死区域心肌肥大、增殖分化和细胞凋亡的改变,探讨DM对MI后心室重构的影响。方法:将实验大鼠分为正常对照组、糖尿病对照组、MI对照组及糖尿病MI组,从各组大鼠的左心室梗死周边取材,采用免疫组化染色法检测转化生长因子-β1(TGF-β1)、增殖细胞核抗原(PCNA),用末端脱氧核苷酸转移酶介导的dUTP末端缺口标记法(TUNEL)检测凋亡细胞,并进行对比分析。结果:DM大鼠MI后非梗死区域存在着明显的心肌肥大、增殖分化和细胞凋亡。试验表明,糖尿病MI组大鼠梗死区周边凋亡细胞及PCNA、TGF-β1的阳性率均明显高于DM对照组及MI对照组(P0.01)。DM对照组大鼠梗死区周边凋亡细胞的比例明显高于MI对照组(P0.01)。结论:DM可增强TGF-β1和PCNA的表达及增加细胞凋亡,三者可能为DM大鼠MI后高心律失常及高死亡率的病理生理基础。

Ventricular remodeling in non-infarcted areas after myocardial infarction in type II diabetic rats

AIM: To explore the effect of diabetes on ventricular remodeling in non-infarcted areas after myocardial infarction in type II diabetic rats by comparing changes of cardiac hypertrophy (TGF-β1), proliferation differentiation (PCNA) and apoptosis (TUNEL). METHODS: Sprague Dawley (SD) rats were randomly divided into blank group, diabetic group, infarcted group and infarcted diabetic group. Samples were obtained from the infarcted diabetic rats in non-infarcted area. Using immunohistochemistry and computer image processing technique, TGF-β1, PCNA and TUNEL expressions were examined in different groups (blank, diabetic, infarcted, infarcted diabetic). RESULTS: After myocardial infarction, the positive rates of TUNEL, PCNA, TGF-β1 in non-infarcted areas in infarcted diabetic group were significantly higher than those in the blank group, diabetic group and infarcted group (P<0.01). Compared with the infarcted group, the positive rate of TUNEL in non-infarcted areas in diabetic group was significantly higher. CONCLUSION: Diabetes increased expressions of cardiac hypertrophy, proliferation and apoptosis in non-infarcted regions, which may be the pathophysiological basis of high morbidity of ventricular arrhythmia and high mortality after myocardial infarction in diabetes.