For example, the administration of exogenous ET-1 produces profound retention of salt and water accompanied by systemic and renal vasoconstriction,12,13 whereas ETA blockade in CKD induces a natriuresis and an increase in renal blood flow.14 It is not possible to easily differentiate the indirect effect of any hemodynamic changes on renal salt and water excretion from direct effects on renal tubular cell function. Here, EDNRA is linked to chronic kidney disease.