eplerenone and Autoimmune-Diseases

Aldosterone blockade reduces morbidity and mortality in patients with heart failure. We studied the effects of eplerenone, a novel aldosterone blocker, on the progression of left ventricular dysfunction and remodeling in rats with dilated cardiomyopathy after autoimmune myocarditis. Twenty-eight days after immunization, the surviving Lewis rats were randomized to 1 month's oral treatment with low-dose eplerenone (group L), high-dose eplerenone (group H) or vehicle (group V). Five of 15 (33%) rats in group V and 3 of 15 (20%) rats in group L died during the course of treatment. High-dose eplerenone significantly reduced cardiomyocyte hypertrophy, heart weight and heart weight to body weight ratio. Eplerenone improved left ventricular function in a dose-dependent manner. Central venous pressure and left ventricular end-diastolic pressure were lower, and +/-dP/dt and fractional shortening were higher in group H than group V. Eplerenone also attenuated myocardial fibrosis and reduced left ventricular mRNA expressions of TGF-beta(1) and collagen-III. Our results indicate that treatment with eplerenone improved left ventricular dysfunction and attenuated left ventricular remodeling in rats with heart failure.

Topics: Animals; Autoimmune Diseases; Cardiomyopathy, Dilated; Collagen Type III; Dose-Response Relationship, Drug; Electrocardiography; Eplerenone; Fibrosis; Hemodynamics; Male; Mineralocorticoid Receptor Antagonists; Myocarditis; Myocardium; Rats; Rats, Inbred Lew; RNA, Messenger; Spironolactone; Transforming Growth Factor beta; Ventricular Dysfunction, Left; Ventricular Remodeling