Renal tubular effects of endothelin-B receptor signaling: its role in cardiovascular homeostasis and extracellular volume regulation

The role of the endothelin-B receptor in vascular homeostasis is controvers ial because the receptor has both presser and depressor effects in vivo. On e potential depressor mechanism of endothelin-B activation is through the p romotion of natriuresis and diuresis in the renal tubule. Recent studies de monstrate that rodents genetically deficient for the endothelin-B exhibit s odium-dependent hypertension due to an absence of tonic inhibition of the e pithelial sodium channel in the distal nephron. These studies suggest that the predominant role of endothelin-B receptors in the basal physiologic sta te may be to regulate renal sodium excretion relative to the level of oral salt intake. Curr Opin Nephrol Hypertens 9:435-439. (C) 2000 Lippincott Wil liams & Wilkins.