Therapeutic Efficacy of a Combination of a 1-Adrenoreceptor (AR) Blocker and 2-AR Agonist in a Rat Model of Postmyocardial Infarction Dilated Heart Failure Exceeds That of a 1-AR Blocker plus Angiotensin-Converting Enzyme

We had proposed previously a novel combination of 2-adre-noreceptor (AR) agonist and 1-AR blocker that in the rat model of postmyocardial infarction (MI) dilated cardiomyopathy ex-ceeds the therapeutic effectiveness of either monotherapy. In the present study, we compared that treatment with a combi-nation of 1-AR blocker and angiotensin-converting enzyme inhibitor (ACEi), a current standard chronic heart failure (CHF) therapy. Two weeks after coronary artery ligation, rats were divided into groups of similar average MI size, measured by echocardiography, and the following 12-month treatments were initiated: fenoterol (250 g/kg/day), a 2-AR agonist, plus metoprolol (100 mg/kg/day), a 1-AR blocker (1-2); meto-prolol plus enalapril (20 mg/kg/day), an ACEi (1-ACEi); and a combination of all three drugs (1-2ACEi). These treatmen