Cardiac endothelin-like immunoreactivity and preproendothelin-1 mRNA expression in human heart failure

Endothelin (ET) induces hypertrophy of cardiomyocytes and increases synthes is of collagen in vitro. Interestingly, these features are hallmarks of the cardiac remodeling taking place in heart failure. The aim of the present s tudy was to examine cardiac ET peptide and preproET-1 mRNA synthesis in hum an heart failure. Cardiac tissue was obtained from 11 patients with end-sta ge heart failure undergoing orthothopic heart transplantation (NYHA III-IV) . Cardiac tissue from nine organ donors served as controls. The specimens w ere examined by immunohistochemistry and mRNA slot blot analyses. Significa ntly stronger ET-1-like immunoreactivity (ET-1-ir) was seen in the left atr ial myocardium of failing hearts compared to the left atrial myocardium of donor hearts. Within each heart, the epicardium showed the strongest ET-1-i r. Left ventricular preproET-1 mRNA expression in the entire group of patie nts did not differ significantly from that of donor hearts. However, hypert rophic obstructive cardiomyopathy may be associated with a twofold increase in left ventricular preproET-1 mRNA. We report an increase in cardiac ET p eptide in human heart failure.