The Renal and Systemic Hemodynamic Actions of Endothelin

The family of biologically active peptides known as the endothelins (ETs) has been the focus of considerable research since the isolation of an endothelial cell constricting factor (EDCF) by Hickey et al. in 1985 (1) and the subsequent cloning of endothelin-1 (ET-1) by Yanagisawa et al., in 1988 (2). Endothelin and endothelinrelated peptides (ET-1, ET-2, and ET-3) have profound effects on a number of hemodynamic variables relating to cardiovascular and renal function. ET-1 is one of the most potent vasoconstrictor agents that has been isolated. Systemic actions of the peptide require concentrations similar to those of angiotensin II and vasopressin (3),whereas the renal hemodynamic potency exceeds other vasoconstrictors by approximately one order of magnitude. In addition, a number of studies have demonstrated that ET-1 possesses significant vasodilator properties, demonstrating that the molecule has rather unique properties among the long list of vasoactive, biologically important molecules.