THE AMNION PRODUCES LITTLE OF THE PROSTAGLANDIN-E2 DETECTED ON THE DECIDUAL SIDE OF HUMAN FETAL MEMBRANES

Cultured intact fetal membrane disks initially produced high levels of prostaglandin E2 (PGE2) on the fetal and maternal sides which decline d during four days of culture. The transfer of a bolus of PGE2 from th e fetal side to the maternal side of the membrane ranged from 1% to 3% after 24 hours of culture, and was a minimum over the period of 48-72 hours from the start of the incubation. To assess the handling of PGE 2 synthesised by the amnion, H-3-arachidonic acid was incorporated int o cultured amnion and into the amnion side of cultured intact fetal me mbrane disks. Labelled amnion released H-3-PGE2 on both sides of the t issue, whereas similarly labelled cultured intact fetal membrane only had detectable levels of H-3-PGE2 on the fetal side. It was calculated that no more than 9.7 +/- 1.4% of the PGE2 synthesised by the amnion crossed to the maternal side of the membrane without being metabolised during the transfer through the membrane. These results are consisten t with similar indirect methods which suggested that PGE2 from the amn ion may have only a limited role in human labor, and indicates the imp ortance of using appropriate culture systems to investigate intra-uter ine prostaglandin production.