prostaglandin-d2 and 5-6-dihydroprostacyclin

The prostaglandins PGE1, PGE2, PGD2, PGF2 alpha, U46619 and 6 beta-PGI1 were administered as bolus injections both separately and in combination with angiotensin II into the fetal circulation of isolated human placental cotyledons perfused in vitro. PGF2 alpha and PGD2 caused small dose-dependent increases in fetal perfusion pressure when compared with U46619 which acted as an extremely potent vasoconstrictor of the fetal-placental vasculature. PGE1 caused very small dose-dependent decreases in fetal perfusion pressure when injected on its own. In combination with angiotensin II, PGE1, PGD2 and 6 beta-PGI1 caused significant, dose-related attenuations of the angiotensin II vasoconstrictive response whereas PGE2, PGF2 alpha and U46619 potentiated the response. Injections of angiotensin II after the infusion of indomethacin into the fetal circulation resulted in a potentiation of angiotensin II induced vasoconstriction. The results indicate that prostaglandins exert their effects on the fetal-placental circulation by modulating the actions of angiotensin II.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Alprostadil; Angiotensin II; Dinoprostone; Drug Interactions; Epoprostenol; Female; Humans; In Vitro Techniques; Perfusion; Placenta; Pregnancy; Prostaglandin D2; Prostaglandin Endoperoxides, Synthetic; Prostaglandins; Prostaglandins D; Prostaglandins E; Prostaglandins, Synthetic; Vasoconstriction