Activation of purinergic receptors (P2) in the renal medulla promotes endothelin-dependent natriuresis in male rats.

Activation of purinergic receptors (P2) in the renal medulla promotes endothelin-dependent natriuresis in male rats. Am J Physiol Renal Physiol. 2016 May 25;:ajprenal.00090.2016 Authors: Gohar EY, Speed JS, Kasztan M, Jin C, Pollock DM Abstract Renal endothelin-1 (ET-1) and purinergic signaling systems regulate Na+ reabsorption in the renal medulla. A link between the renal (ET-1) and purinergic systems was demonstrated in-vitro, however, the in-vivo interaction between these systems has not been defined. To test whether renal medullary activation of purinergic (P2) receptors promotes ET-dependent natriuresis, we determined the effect of increased medullary NaCl loading on Na+ excretion and inner medullary ET-1 mRNA expression in anesthetized adult male Sprague Dawley rats in the presence and absence of purinergic receptor antagonism. Isosmotic saline (NaCl; 284 mOsmol/kg H2O) was infused into the medullary interstitium (500 μl/h) during a 30 min baseline urine collection period, followed by isosmotic or hyperosmotic saline (1800 mOsmol/kg H2O) for two further 30 min urine collection periods. Na+ excretion was significantly increased during intramedullary infusion of hyperosmotic saline. Compared with isosmotic saline, hyperosmotic saline infused into the renal medulla caused significant increases in inner medullary ET-1 mRNA expression. Renal intramedullary infusion of the purinergic (P2) receptor antagonist, suramin, inhibited the...
Source: Am J Physiol Renal P... - Category: Urology & Nephrology Authors: Tags: Am J Physiol Renal Physiol Source Type: research