Prostaglandin Biosynthesis in Umbilical Vessels

Abstract

Prostaglandin biosynthesis in umbilical vessels was investigated in patients of normal pregnancy, pregnancy induced hypertension, diabetes mellitus and intrauterine growth retardation of unknown cause. To the homogenates of umbilical vessels, isotope labeled arachidonic acid was added and incubated for 30 min. Then the biosynthetic products were extracted and identified by silicic acid column chromatography, thin layer chromatography and HPLC. In normal pregnancy, PG biosynthesis was examined in both arteries and veins. Biosynthetic products in arteries and veins were 6keto PGF_1α, PGF_2α, PGE₂, PGD₂, 15HETE and 8, 15 diHETE. In the umbilical veins, conversion rates to 15HETE and 8, 15 diHETE were higher than those in the umbilical arteries. Conversion rates to 6keto PGF_1α were lower in PIH and IUGR patients than in the normal control. This means that PGI₂ synthesis in those patients was reduced. On the other hand, hydroxyacid biosynthesis in patients with PIH, DM and IUGR was increased. Therefore in pathological conditions, bioconversion of arachidonic acid to PGI₂ is reduced and it may be said that blood circulation in the umbilical vessels in those patients is also reduced.