EP3 receptor regulates water excretion in response to high salt intake.

EP3 receptor regulates water excretion in response to high salt intake. Am J Physiol Renal Physiol. 2016 Jul 27;:ajprenal.00589.2015 Authors: Hao S, DelliPizzi A, Quiroz-Munoz M, Jiang H, Ferreri NR Abstract The mechanisms by which prostanoids contribute to the maintenance of whole body water homeostasis are complex and not fully understood. The present study demonstrates that an EP3-dependent feedback mechanism contributes to the regulation of water homeostasis under high salt conditions. Rats on a normal diet and tap water were placed in metabolic cages and given either sulprostone (20 µg/kg/day) or vehicle for 3 days to activate EP3 receptors in thick ascending limb (TAL). Treatment was continued for another 3 days in rats given either 1% NaCl in the drinking water or tap water. Sulprostone decreased expression of COX-2 expression by approximately 75% in TAL tubules from rats given 1% NaCl concomitant with a ~60% inhibition of COX-2-dependent PGE2 levels in the kidney. Urine volume increased after ingestion of 1% NaCl, but was reduced ~40% by sulprostone. In contrast, the highly selective EP3 receptor antagonist (L-798106, 100 µg/kg/day), which increased COX-2 expression and renal PGE2 production, increased urine volume in rats given 1% NaCl. Sulprostone increased expression of AQP2 in inner medullary collecting duct plasma membrane in association with an increase in phosphorylation at Ser269 and decrease in Ser261 phosphorylati...
Source: Am J Physiol Renal P... - Category: Urology & Nephrology Authors: Tags: Am J Physiol Renal Physiol Source Type: research