Acute infusion of angiotensin II regulates organic catión transporters function in the kidney: its impact on renal dopaminergic system and sodium excretion

KOUYOUMDZIAN, N.M.; RUKAVINA MIKUSIC, NATALIA LUCÍA; ROBBESAUL G; SUSANA GORZALCZANIC; ANDREA CARRANZA; VA TRIDA; BELISARIO E. FERNÁNDEZ; CHOI, M.R.

HYPERTENSION RESEARCH

NATURE PUBLISHING GROUP

Lugar: Londres; Año: 2020

0916-9636

A close relationship between angiotensin II (ANG II) and renal dopaminergic system (RDS) has been reported. Our aim was to study whether renal dopamine and ANG II are able to interact to modify renal sodium handling and elucidate the mechanism implied. Anesthetized male Sprague Dawley rats were used in the experiments. ANG II, exogenous dopamine and decynium-22 (or D-22, an isocyanine that specifically blocks electrogenic organic cation transporters named OCTs), were infused in vivo for 120 minutes. We determined renal and hemodynamic parameters, renal Na+,K+?ATPase, OCTs activity and urinary dopamine concentration. We also evaluated D1 Receptor, electroneutral organic cation transporters (OCTNs) and OCTs expression. ANG II decreased renal excretion of sodium in the presence of exogenous dopamine, increased Na+,K+?ATPase activity and decreased urinary dopamine concentration. All these effects were prevented by D-22. The infusion of ANG II did not affect the expression of D1 Receptor, OCTs and OCTNs. However, OCTs activity was diminished by the presence of ANG II. Although ANG II did not alter the expression of D1 Receptor, OCTs and OCTNs in renal tissues, it modified OCTs activity and thereby decreased urinary dopamine concentration, showing a novel mechanism by which ANG II decreases dopamine transport and its availability in the tubular lumen to stimulate D1 Receptor. This study demonstrates a relationship between ANG II and dopamine to counteract its effects on sodium excretion.