Role of endothelin in the maintenance of blood pressure in conscious rats with chronic heart failure: Acute effects of the endothelin receptor antagonist Ro 47-0203 (bosentan)

Abstract

Background: Endothelin (ET) is a potent vasoconstrictor, and its concentration is increased in patients with heart failure. The purpose of this study was to investigate the role of endothelin in heart failure by use of a rat model. Methods and Results: Experiments were performed on rats at 1 through 16 weeks after sham operation or coronary artery ligation. Rats with left ventricular end-diastolic pressures >15 mm Hg were considered to have chronic heart failure (CHF), while the others were considered to have uncomplicated myocardial infarction (MI). There were increased ET-1 concentrations in CHF rats at weeks 1 to 16 (Sham, 20±0.5 pg/mL, n=45; CHF, 31±2 pg/mL, n=50; P