The biology of the family of endogenous autocrine peptides known as the endothelins (ETs) has been a source of intense study for researchers since 1988, following the identification of ET-l as the previously described endothelium-derived contractile factor. Initial interest focussed on the actions of the ETs in the cardiovascular system, and this remains the pri- mary source of published work involving these peptides. Importantly, evi- dence is mounting for a significant mediator role for ET-l in cardiovascu- lar diseases including systemic hypertension and congestive heart failure. However,...