Effects of NG-monomethyl-L-arginine, indomethacin, and aspirin on the vasodepressor response to low doses of endothelin-1 and endothelin-3 in rats

Endothelin receptor heterogeneity, G-proteins, and signaling via cAMP and cGMP cascades

1. The endothelins (ETs) are potent vasoactive peptides which are involved in diverse biological processes, such as contraction, neuromodulation, and neurotransmission, as well as in certain pathophysiological conditions including cardiac and renal failure. 2. The diversity of action of ETs may be attributed to (i) the existence of a number of receptor subtypes, and (ii) the G-protein-mediated activation of different signal transduction pathways. 3. The combined action of these two variables modulates the response, since different receptor subtypes can stimulate and/or inhibit the cAMP and cGMP cascades.

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, neuromodulation, and neurotransmission, as well as in various pathophysiological conditions, such as renal and heart failure. The diversity of actions of ETs may be explained in terms of (1) the existence of several receptor subtypes and (2) the activation of different signal transduction pathways. This review summarizes the state of the art in this intensively studied field, with particular focus on structural aspects, receptor heterogeneity, coupling of receptors to G-proteins, and signal transduction mechanisms mediated by the activation of ET-receptors.