A comparison of the hemodynamic responses of systematic and uteroplacental vasculature to angiotensin in conscious guinea pigs.

Hemodynamic studies were performed in 11 conscious pregnant guinea pigs using radioactive microspheres to calculate the effects of angiotensin II (AII) infusion. A dose-dependent increase of the mean arterial pressure and systemic vascular resistance during AII infusion was observed. A significant increase in in uteroplacental flow also occurred without a change in cardiac output or uteroplacental vascular resistance. These data demonstrate that the systemic and uterine vasculatures of the pregnant guinea pig have different responses to AII infusion.