Localization of 15-Hydroxy Prostaglandin Dehydrogenase in Human Fetal Membranes, Decidua, and Placenta during Pregnancy

Localization of NAD(+)-dependent 15-hydroxy prostaglandin dehydrogenase (type I-PGDH) may influence local concentrations of bioactive eicosanoids within intrauterine tissues. In early pregnancy (6-9 weeks), IR-PGDH was localized by immunohistochemistry to syncytiotrophoblast, cytotrophoblast, and intermediate trophoblast of placenta. At 23-30 weeks of gestation and at term IR-PGDH was present in syncytiotrophoblast and intermediate trophoblast, but not in cytotrophoblast in placenta. It was absent from amnion, and distributed within the trophoblast cell layer of extraplacental chorion variably at 23-30 weeks, but consistently at term. We speculate that PGDH is ideally localized to metabolize and to maintain low concentrations of primary prostaglandins in the fetal membranes for much of gestation.