The Effect of Prostaglandin E₁on the Pressor Response to Angiotensin II in Second Trimester Human Pregnancy and in the Non-Pregnant Subject

Abstract

The effect of a simultaneous infusion of prostaglandin E₁ (PGE₁) on the pressor response to angiotensin II (AII) has been studied in 8 pregnant and six non-pregnant subjects to date. PGE₁ 15 ng kg⁻¹ min⁻¹ had no effect on basal blood pressures in the pregnant patients, but increased heart rate by 9.1 ± 1.6 bpm (P<0.001). Six of these eight wanen had scanewhat diminished pressor responses to AII (4, 8 and 16 ng kg⁻¹ min⁻¹) during PGE₁ infusion; this difference reached statistical significance at the lowest dose of AII (P<0.05). PGE₁ 10 ng kg⁻¹ min⁻¹ slightly increased basal diastolic pressure in the non-pregnant subjects (P<0.05) and increased heart rate by a similar amount (8.4 ± 1.8 bpm, P<0.01). Again, the overall pressor response to AII was sanewhat diminished in the majority of these subjects. The pregnant patients exhibiting the greatest initial pressor response to AII were those in whom the greatest decrease in response was seen; this correlation achieved statistical significance at 8 and 16 ng kg⁻¹ min⁻¹ AII (P<0.01, P(0.002 respectively). A similar trend was apparent in the non-pregnant subjects.