Further observations on the nature of pressor responsivity to angiotensin II in human pregnancy.

The pressor dose of infused angiotensin II was determined before and after rapid volume expansion with 800 to 1075 ml of high-hematocrit blood. There was no remarkable change in sensitivity to infused angiotensin demonstrated except in two instances in which transient volume overload developed. The data support the hypothesis that increased angiotensin sensitivity observed in patients with pregnancy-induced hypertension is the consequence of increased vascular responsivity.