Role of Endothelin-1 in Clinical Hypertension

Abstract

Hypertension is the most common risk factor worldwide for cardiovascular morbidity and mortality.1,2 Currently it is estimated that a quarter of the world’s adult population is hypertensive, and this number is projected to increase to ≈30% by 2025.1 Although, there exist a number of drug therapies for hypertension, blood pressure (BP) control to target is still only achieved in ≈30% of patients.3 Over the last 20 years, novel licensed therapies have primarily focused on the renin-angiotensin-aldosterone system. Endothelin (ET) receptor antagonism represents an innovative, but as yet only partially explored, alternative approach in the management of hypertension. A review in Hypertension 10 years ago outlined the potential role that ET-1 may play in the development of hypertension,4 as proposed by Yanagisawa et al in their original Nature article in 1988.5 This largely focused on preclinical data because, at that time, there was only 1 published study of ET receptor antagonism in patients with essential hypertension.6 There were also few data that focused on the relative benefits of selective or mixed ET blockade. Finally, the lack of longer-term data on safety and tolerability for these drugs made their place in the antihypertensive armamentarium unclear. In this review we aim to answer many of these questions and outline some of the key findings in this field from the last decade. The ET family consists of three 21-amino acid peptides (ET-1, ET-2, and ET-3) with powerful vasoconstrictor and pressor properties.7 Of the 3 peptides, ET-1 is the major vascular isoform and of most importance in the cardiovascular system.8 The gene product is the 212-amino acid prepro-ET-1. This is cleaved to big ET-1, after which an ET-converting enzyme (ECE) catalyzes the generation of the biologically active ET-1 and a C-terminal fragment. ET-1 acts by binding to …