Endothelin antagonism in pulmonary hypertension, heart failure, and beyond

Abstract
The endothelin family consists of three closely related peptides, ET-1, ET-2, and ET-3, each 21 amino acids in length and derived from separate genes. ET-1[1–21] is the main isoform produced in the cardiovascular system and about which most is known; ET-2 is mainly produced within the kidney and intestine, whereas ET-3 is predominantly found within the central nervous system (tables 1 and 2). However, the roles of ET-2 and ET-3, except in embryonic development, remain unclear.