The Transfer of Prostaglandin E2 Across Ovine Fetal Membranes In Vivo

Abstract

Objective: This study investigated whether prostaglandin E₂ (PGE₂) can cross intact fetal membranes in vivo.

Methods: We have developed a novel ovine model using in vivo dialysis systems, positioned between the fetal membranes and decidua and in the amniotic cavity. Sheep were given 25 μCi, 50 ng [³H]PGE₂ or 1 mg PGE₂ to the amniotic cavity, and radioactivity or PGE₂/PGEM concentrations in dialysates were determined.

Results: Endogenous basal PGE₂ concentrations were significantly higher iun extra-amniotic than in intra-amniotic dialysates (715 ± 436 versus 80 ± 31 pg/mL; mean ± standard error of the mean; p < .05). After injection of [³]PGE₂ into the amniotic cavity, no radioactivity was detected in the extraamniotic dialysate, and this was not influenced by labor induced by ACTH administration to the fetus. In contrast, intra-amniotic injection of 1 mg PGE₂ resulted in marked transfer of PEG₂ across the fetal membranes to the extra-amniotic dialysis system.

Conclusion: These results suggest that PGE₂ can cross the ovine fetal membranes in vivo, escaping metabolism in the chorion.

Keywords

Prostaglandin E2 fetal membranes parturition ovine model

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