Kidney Dopamine D1-like Receptors and Angiotensin 1-7 Interaction Inhibits Renal Sodium Transporters.

This study aims to investigate the hypothesis that Ang 1-7 could regulate sodium homeostasis by modulating renal dopamine system. Sprague Dawley rats were infused with saline alone (vehicle) or saline with Ang 1-7, Ang 1-7 antagonist A-779, DR agonist SKF38393, and antagonist SCH23390. Infusion of Ang 1-7 caused significant natriuresis and diuresis when compared to saline alone. Both natriuresis and diuresis were blocked by A-779 and SCH23390. SKF38393 caused a significant, SCH23390 sensitive, natriuresis and diuresis and A-779 had no effect on SKF38393 response. Concomitant infusion of Ang 1-7 and SKF38393 did not show a cumulative effect when compared to either agonist alone. Treatment of renal proximal tubules with Ang 1-7 or SKF38393 caused a significant decrease in Na/K-ATPase and Na/H-Exchanger (NHE) 3 activity. While SCH23390 blocked both Ang 1-7 and SKF38393 induced inhibition, DR response was not sensitive to A-779. Additionally, Ang 1-7 activated protein kinase (PK) G, enhanced tyrosine hydroxylase activity via serine-40 phosphorylation and increased renal dopamine production. These data suggest that Ang 1-7 via PKG enhances tyrosine hydroxylase activity which increases renal dopamine production and activation of DR and subsequent natriuresis. These studies provide evidence for a unidirectional functional interaction between two G protein-coupled receptors to regulate renal sodium transporters and induce natriuresis. PMID: 31411069 [PubMed - as supplied by p...
Source: American Journal of Physiology. Renal Physiology - Category: Physiology Authors: Tags: Am J Physiol Renal Physiol Source Type: research