Comparative effects of losartan and captopril on ventricular remodeling and function after myocardial infarction in the rat.

OBJECTIVE: To determine the effects of losartan and captopril treatment on ventricular remodeling and function after myocardial infarction in rats. METHODS: Thirty-two rats with MI induced by coronary ligation after seven days were divided into four groups randomly and treated with captopril(2 g.liter-1, group A), losartan(10 mg.kg-1.d-1, group B), losartan(30 mg.kg-1.d-1, group C) and placebo (no drug, group D) for six weeks, respectively. Sham-operated rats(group E) served as controls. Echocardiography was performed at 1 and 7 weeks after MI, respectively. RESULTS: Compared with the results before treatment, both LV end-diastolic internal diameter and volume decreased significantly and the thickened posterior wall was reversed in group A, B and C; the peak early filling velocity decreased whereas the peak velocity was increased in these three groups. There are no significant difference among the three treated groups. However, LV end-diastolic internal diameter and the E/A were still increased, whereas the thickness of anterior wall and the peak velocity of LV outflow were decreased in group A, B, and C after treatment comparing with group E. CONCLUSION: Both angiotensin converting enzyme inhibitor and angiotensin II receptor antagonist can prevent the ventricular remodeling and improve the ventricular function.