Prostaglandin dehydrogenase mRNA in baboon intrauterine tissues in late gestation and spontaneous labor

The present study was designed to characterize prostaglandin dehydrogenase (PGDH) mRNA expression in critical intrauterine tissues of pregnant baboons in late gestation and at spontaneous labor. In addition, we determined reg ulatory effects of betamethasone in vivo on chorionic and placental PGDH mR NA expression. PGDH mRNA was present in chorion, decidua, lower uterine seg ment, fundal myometrium, and cervix in late gestation but undetectable in a mnion. PGDH mRNA significantly decreased in decidua and cervix during late gestation and in chorion and fundus during spontaneous labor. PGDH mRNA in lower uterine segment, decidua, cervix, and placenta was unchanged during s pontaneous labor from late gestation levels. Betamethasone had no effect on chorionic and placental PGDH mRNA expression. In summary, our data suggest that PGDH mRNA expression is tightly controlled in gestation- and tissue-s pecific manners. Decreased chorionic and fundal PGDH abundance during labor and decreased decidua and cervical PGDH mRNA in late gestation allow local uterine prostaglandin accumulation and assist prostaglandin transfer to my ometrium. Local differences in PGDH function may regulate tissue- and regio n-specific requirements for prostaglandins to promote and complete labor.