The effect of prostaglandin E1 upon the pressor and hormonal response to exogenous angiotensin II in human pregnancy.

The effect of prostaglandin E1 (PGE1) on the pressor and hormonal response to angiotensin (ANG) II has been studied in 22 women in second trimester pregnancy. Three-point dose-response curves were initially determined for all women. Eleven then received an infusion of PGE1 while the remainder received an infusion of normal saline as controls. The dose-response curves to ANG II were re-studied after a period of stabilization. Although assignation to treatment group was random, differences were found in age and basal blood pressure between the control group and those given PGE1. The pressor data from the PGE1 group were thus split by age for analysis. The administration of ANG II alone was associated with significant (P less than 0.001 at all doses) pressor effects without accompanying bradycardia. Plasma renin concentration (PRC) was suppressed (P less than 0.001). Plasma aldosterone concentration rose (P less than 0.001), the magnitude of the rise being directly associated with the plasma ANG II concentrations achieved (P less than 0.05). The infusion of PGE1 had no significant effect on basal blood pressure, but evoked a sustained tachycardia in both age groups (P less than 0.001). Basal hormone concentrations were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)