Response of ovine uterine blood flow to angiotensin II: effect on the fetus.
The effect of intravenous infusion of angiotensin II (2 to 200 ng/kg/min) on uterine blood flow and cardiovascular performance was studied in the normotensive, unanesthetized pregnant ewe. With low rates of infusion (2 to 4 ng/kg/min), only a transient increase in uterine blood flow, lasting 1 to 3 minutes, was observed. Higher rates (110 to 200 ng/kg/min) of infusion caused a decrease in uterine blood flow; this decrease was significantly correlated to the dose. Angiotensin II also caused a significant decrease in the maternal heart rate and an increase in mean maternal arterial blood pressure as the rate of infusion was increased. A high rate of infusion resulted in decreased fetal heart rate and PaO2, probably due to a marked reduction in uteroplacental blood flow.
D000804:Angiotensin II / Q000008:administration & dosage*; D000818:Animals; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005318:Fetal Heart / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D011247:Pregnancy; D011270:Pregnancy, Animal; D012039:Regional Blood Flow / Q000187:drug effects; D012756:Sheep / Q000502:physiology*; D014599:Uterus / Q000098:blood supply*
D000804:Angiotensin II