The renal functional response to Ang(1–7) infusion in DOCA‐salt hypertensive rats.

Abstract

Angiotensin 1–7 (Ang1–7) has natriuretic properties at the kidney that counterbalance the anti‐natriuretic actions of angiotensin II. This study investigated whether the renal actions of Ang1–7 are deranged in Deoxycorticosterone (DOCA) salt hypertensive states where the renin‐angiotensin system (RAS) is suppressed. Groups of anaesthetised male Wistar rats (n=6) were prepared for renal interstitial infusion at 1ml/h of Ang 1–7 (3×10–9 M) into the left kidney and cannulation of its ureter. Data, means±SEM were subject to one‐way ANOVA. Ang 1–7 had no effect on blood pressure, at 118mmHg for control rats and 153mmHg for DOCA Hypertensive rats. In control rats, urine volune (UV), significantly increased from 100.9±6.9 to139.1±4.5μl/min, sodium excretion (UVNa), from 16.0±1.3 to 24.3±1.0μmol/min and fractional sodium excretion (FENa) by 2.3±0.5 to 2.9±0.5% (all P<0.05). Intra‐renal infusion of the same dose of Ang 1–7 in the DOCA model had no effect on the excretory variables. The reasons for the lack of response to the Ang (1–7) are uncertain but one possibility is that the action of Ang(1–7) may correlate with the level of RAS activation.