Changes In Expression Levels Of Angiotensin Ⅱ And Its Receptors In A Model Of Stress-induced Cardiomyopathy

Objectives:To explore the correlation of stress ardiomyopathy and angiotensin II and its receptors in animal model of stress cardiomyopathy.Methods:A model of SIC was established in rabbits by vagal electrical stimulation. We will take ECG tracings and take the rabbit myocardial tissue, to observe myocardial injury by HE staining. The serum concentration of angiotensin Ⅱ and angiotensin (1-7) was detected by enzyme-linked immunosorbent assay.Expression of angiotensin-Ⅱ receptors was measured by western blotting and real-time RT-PCR, with localization detected by immunofluorescent staining. ACE2expression in the myocardium was measured by western blotting.Results:1. Compared with the control group, the myocardial cell cytoplasm of experimental group appeared vacuoles and the myocardial fibre is disorder through HE dyschroia by vagal electrical stimulation.2. From1day after vagal stimulation, concentrations of angiotensin Ⅱ were significantly higher in the experimental group than those in the control group (P<0.05)3. Stress induced a time-dependent decrease in AT1expression and a time-dependent increase in AT2expression only in the apical portion of the myocardium (P<0.05)4. Immunofluorescent staining showed clear immunoreactivity for AT1and AT2in scattered cells in the myocardium of basal and apical portions. 5. From3days after vagal stimulation, angiotensin (1-7) levels were significantly lower in the experimental group compared with the control group (P<0.05) Expression of ACE2protein was significantly downregulated in the experimental group compared with the control group from3days after vagal stimulation (P<0.05)Conclusion:1. A model of SIC was established in rabbits by vagal electrical ulation.2. Expression of angiotensin II, its receptors, ACE2and angiotensin (1-7) was altered in response to SIC.3. The renin-angiotensin system could represent a therapeutic target in the prevention of SIC.