The endothelin system as target for therapeutic interventions in cardiovascular and renal disease

Endothelins including its most abundant isoform, endothelin-1 (ET-1), are peptides acting as vasoconstrictors when binding to ET_A and ET_B receptors, and, in addition to their distinct roles in normal physiology, endothelins have a central role in the pathophysiology of many diseases including cardiovascular and renal diseases. Endothelin-1 (ET-1), the most potent vasoconstrictor in the cardiovascular system, regulates basal vascular tone and glomerular hemodynamics. ET-1 is involved also in vascular and cardiac hypertrophy, inflammation, and in the development and progression of cardiovascular diseases - e.g. essential hypertension, atherosclerosis, coronary artery disease, congestive heart failure, pulmonary arterial hypertension and cerebrovascular disease and renal diseases - e.g. acute renal failure, polycystic kidney disease and chronic kidney disease. Not surprisingly, the ET system has become a target for therapeutic interventions that now include a few already established and some new promising agents. In this narrative review, we summarize physiologic properties of the ET system, focusing especially on ET-1, and its role in the pathophysiology of ET system activated diseases, and discuss the potentials of therapeutic interventions targeting the ET system in cardiovascular and renal diseases. While ET receptor antagonists have already revolutionized the management of idiopathic pulmonary arterial hypertension, so far, this class of drugs have failed as medication for congestive heart failure. Clinical trials continue to explore new applications of endothelin receptor antagonists in treatment-resistant hypertension and chronic kidney disease and have shown some benefits in the latter group by reducing proteinuria; however, they have not been approved yet. We conclude that larger clinical trials are needed to validate the use of ET receptor antagonists in ET system activated diseases.