Endothelin 1

Abstract: Endothelins are a newly described peptide family consisting of three peptides (ET-1, ET-2 and ET-3) which are the most potent vasoconstrictive peptides known. They are crucial in the regulation of vascular smooth muscle tone. The diverse functions of endothelins are thought to be mediated by interaction with many different receptors coupled to the inositol phosphate/calcium ion messenger pathway. However, because of the structural resemblance of the three peptides, the presence and nature of multiple endothelin receptors remain to be elucidated. We report here the cloning of a complementary DNA encoding a bovine endothelin receptor, which has a transmembrane topology similar to that of other G protein-coupled receptors and shows specific binding, with the highest selectivity to ET-1 in animal cells transfected with the cloned cDNA. This receptor messenger RNA is widely distributed in the central nervous system and peripheral tissues, particularly in the heart and lung. Our results support the view that there are other receptor subtypes.

Abstract: ENDOTHELIN-1 was initially identified as a 21-residue potent vasoconstrictor peptide produced by vascular endothelial cells, but was subsequently found to have many effects on both vascular and non-vascular tissues1,2. The discovery of three isopeptides of the endothelin family3, ET-1, ET-2 and ET-3, each possessing a diverse set of pharmacological activities of different potency, suggested the existence of several different endothelin receptor subtypes3–7. Endothelins may elicit biological responses by various signal-transduction mechanisms, including the G protein-coupled activation of phospholipase C and the activation of voltage-dependent Ca2+ channels8–10. Thus, different subtypes of the endothelin receptor may use different signal-transduction mechanisms. Here we report the cloning of a complementary DNA encoding one subtype belonging to the superf amily of G protein-coupled receptors. COS-7 cells transfected with the cDNA express specific and high-affinity binding sites for endothelins, responding to binding by the production of inositol phosphates and a transient increase in the concentration of intracellular free Ca2+. The three endothelin isopeptides are roughly equipotent in displacing 125I-labelled ET-1 binding and causing Ca2+ mobilization. A messenger RNA corresponding to the cDNA is detected in many rat tissues including the brain, kidney and lung but not in vascular smooth muscle cells. These results indicate that this cDNA encodes a 'nonselective' subtype of the receptor which is different from the vascular smooth muscle receptor.

Abstract: Background Pulmonary hypertension is characterized by an increase in vascular tone or an abnormal proliferation of muscle cells in the walls of small pulmonary arteries. Endothelin-1 is a potent endothelium-derived vasoconstrictor peptide with important mitogenic properties. It has therefore been suggested that endothelin-1 may contribute to increases in pulmonary arterial tone or smooth-muscle proliferation in patients with pulmonary hypertension. We studied the sites and magnitude of endothelin-1 production in the lungs of patients with various causes of pulmonary hypertension. Methods We studied the distribution of endothelin-1-like immunoreactivity (by immunocytochemical analysis) and endothelin-1 messenger RNA (by in situ hybridization) in lung specimens from 15 control subjects, 11 patients with plexogenic pulmonary arteriopathy (grades 4 through 6), and 17 patients with secondary pulmonary hypertension and pulmonary arteriopathy of grades 1 through 3. Results In the controls, endothelin-1-like immu...

Abstract: Objective: To explore the role of endothelin-1, a potent endothelial-derived vasoconstrictor peptide, in pulmonary hypertension, by measuring its concentration in arterial and venous plasma. Design...