Prostaglandins in the umbilical and uterine circulations during late pregnancy in the ewe

Prostaglandins (PG) E and F, and 13,14-dihydro-15-keto-prostaglandin F (PGFM) were measured in plasma collected from the umbilical artery and vein, the maternal carotid artery, and the utero-ovarian vein of pregnant sheep between 116 and 139 days of gestation. PGE levels were greater than PGF levels in the umbilical artery and vein and the maternal carotid artery, but not in the utero-ovarian vein. PGFM exceeded PGF in samples from all vessels. There was a significant vein-to-artery concentration difference for PGF and PGFM, but not for PGE, in the umbilical circulation. Utero-ovarian concentrations of all 3 PGs generally exceeded their concentrations in the maternal caroitd artery.