Loss of endothelin B receptor function impairs sodium excretion in a time- and sex-dependent manner.

Loss of endothelin B receptor function impairs sodium excretion in a time- and sex-dependent manner. Am J Physiol Renal Physiol. 2016 Aug 31;:ajprenal.00103.2016 Authors: Johnston JG, Speed JS, Jin C, Pollock DM Abstract Recent studies suggested a direct link between circadian rhythms and regulation of sodium excretion. Endothelin-1 (ET-1) regulates sodium balance by promoting natriuresis through the endothelin B receptor (ETB) in response to increased salt in the diet, but the effect that the time of day has on this natriuretic response is not known. Therefore, this study was designed to test the hypothesis that ETB receptor activation contributes to the diurnal control of sodium excretion, and that sex differences contribute to this control as well. 12-hour urine collections were used to measure sodium excretion. On day 3 of the experiment, a NaCl load (900 µEq) was given by oral gavage either at Zeitgeber [ZT] time 0 (inactive period) or ZT12 (active period) to examine the natriuretic response to the acute salt load. Male and female ETB deficient (ETB def) rats showed an impaired natriuretic response to a salt load at ZT0 compared to their respective transgenic controls (Tg cont). Male ETB def rats showed a delayed natriuretic response to a salt load given at ZT12 compared to male Tg cont, a contrast to the prompt response shown by female ETB def rats. Treatment with ABT-627, an ETA receptor antagonist, improved the natriuretic r...
Source: Am J Physiol Renal P... - Category: Urology & Nephrology Authors: Tags: Am J Physiol Renal Physiol Source Type: research