ENDOTHELIN RECEPTOR SUBTYPES AND THEIR ROLE IN TRANSMEMBRANE SIGNALING MECHANISMS

The endothelins (ETs) are potent vasoactive peptides that appear to be involved in diverse biological actions, for example, contraction, neu romodulation, and neurotransmission, as well as in various pathophysio logical conditions, such as renal and heart failure. The diversity of actions of ETs may be explained in terms of (1) the existence of sever al receptor subtypes and (2) the activation of different signal transd uction pathways. This review summarizes the state of the art in this i ntensively studied field, with particular focus on structural aspects, receptor heterogeneity, coupling of receptors to G-proteins, and sign al transduction mechanisms mediated by the activation of ET-receptors.