Effect of carvedilol on cardiac function and left ventricular remodeling in rats after acute myocardial infarction

Objective: To observe the effect of carvedilol injection on left ventricular function and collagen remodeling in rat with myocardial infarction. Methods: Sixty rats with a model of myocardial infarction were randomly divided into nine groups. The rats of therapeutical group were treated with carvedilol injection (2 mg/d intraperitoneal injection) and/or captopil (2 g/L drinking water) . Acute myocardial infarction ( AMI) group did not receive drug treatment. The animals were sacrificed at 4 weeks and 8 weeks after coronary artery ligation. The levels of plasma angiotensin II and plasma aldosterone and left ventricle function were determined at different time. The collagen content and the ratio of type I and III collagen of noninfarcted area were also assessed. Results: Compared with AMI group, the levels of plasma and myocardium angiotensin II and plasma aldosterone in both carvedilol and captopil group decreased at the eighth week (P0.05). In addition, carvedilol improved systolic and diastolic function (P0. 05). Compared with sham group, both collagen content and the ratio of type I / III collagen of noninfarcted area increased in AMI4 and AMI8 group (P0. 05). The hydroxyproline levels and the ratio of type I/III collagen significantly decreased after carvedilol and/or captopil treatment , compared with AMI group at 4 or 8 week (P 0. 05). Conclusion: Carvedilol can improve cardiac function after myocardial infarction and has beneficial effect on left ventricular remodeling.