Changes of cardiac structure and AngⅡ in streptozotocin-induced diabetic cardiomyopathy rats / 西安交通大学学报(医学版)

ABSTRACT

Objective To explore the changes of cardiac structure and function in streptozotocin (STZ)-induced diabetic cardiomyopathy (DCM)rats so as to detect the level of angiotensinⅡ (AngⅡ)in blood and the myocardium and illuminate the role of AngⅡ in DCM.Methods We randomly divided 30 SD rats into control group and DCM group (which received a single injection of streptozotocin,65 mg/kg).The changes of cardiac structure and function were observed by ultrasonic cardiogram at the end of 16 weeks after injection.Then the changes in the myocardium were also analyzed by using hemotoxylin and eosin staining and Sirius red staining.The level of AngⅡ in blood was tested by radioimmunoassay.The expression of AngⅡ in the myocardium was detected by immunofluorescence. Results Compared with those of the controls,the hearts were dilated in DCM rats accompanied with cardiac dysfunction.There were significant increases in LVEDd,LVESd,LVEDv,and LVESv but decrease in LVEF (P <0.05).There were arrangement disorder and hypertrophic cardiomyocytes in DCM.Then the fibrosis area of DCM was significantly increased compared with that of the controls.The level of AngⅡ in blood and myocardium was significantly higher in DCM than in controls.At the same time,Pearson analysis revealed that the level of AngⅡ in blood was positively related to the collagen content of myocardium (r =0.907,P <0.05).Conclusion Our study provides experimental evidence that AngⅡ plays an important role in myocardial fibrosis of DCM.