Changes in myometrial and placental 15-hydroxyprostaglandin dehydrogenase with ovine parturition: production of prostaglandin metabolites in vitro and in vivo

Summary. 15-Hydroxyprostaglandin dehydrogenase (PGDH) was measured in vitro in myometrium and maternal cotyledons from 6 sheep and in fetal cotyledons from 3 sheep before and after parturition. Maternal cotyledons contained more PGDH than fetal cotyledons or myometrium. At parturition, PGDH activity decreased in myome-trium but increased in fetal and maternal placental tissue. The enzymatic activity observed in vitro did not result in a large, consistent release of prostaglandin F metabolites into the utero-ovarian vein in vivo, and such activity may have a strictly localized effect in ovine parturition