Angiotensin II Vascular Reactivity and Angiotensin II Metabolism in Pregnant and Non-Pregnant Baboons (Papio Hamadryas)

Abstract

A serial study with cardiac catheterization of pregnant baboons was carried out to determine the effect of gestation on vascular responsiveness to exogenous angiotensin II (AII) over a ten-fold dose range, using the same animals as non-pregnant controls. The effect of pregnancy on arterial AII concentration, before and during AII administration, was also examined. There was a significant increase in endogenous AII from 4 weeks gestation, with progressive reductions in both total peripheral resistance and vascular reactivity to exogenous AII through early pregnancy. There were no significant reductions in the arterial plasma concentrations of AII achieved by AII infusion during pregnancy to account for its diminished effect on vascular resistance