Altered angiotensin-prostanoid interactions in umbilical arteries in pregnancy-induced hypertension

The production rate of four prostanoids (PGE2, PGF2 alpha, 6-keto-PGF1 alpha and TXB2) in human umbilical cords from normal pregnancies (control) and cases with pregnancy-induced hypertension (PIH) were compared. The cords in the PIH-group produced significantly less 6-keto-PGF1 alpha and more TXB2 than did those in the control-group. Production rates of PGE2 and PGF2 alpha were almost equal in the two groups. After stimulation with angiotensin II the PIH-cords displayed a far smaller increase in 6-keto-PGF1 alpha production compared to the control cords. The responses in PGE2 and PGF2 alpha production were again equal in the two groups. The present results indicate that the angiotensin-prostanoid interactions are disturbed in fetal as well as in maternal vessels. Such a disturbance may explain the observed relative hypersensitivity to angiotensin II observed in gravidae prone to develop pregnancy-induced hypertension.