Arachidonic acid metabolism by lipoxygenase pathways in intrauterine tissues of women at term of pregnancy.

Intrauterine tissues from women at term of pregnancy metabolized arachidonic acid by way of lipoxygenase pathways that included 5-, 12-, and 15- lipoxygenases. The major lipoxygenase product formed by amnion obtained before labor was leukotriene B4 and after labor was 12- hydroxyeicosatetraenoic acid (12-HETE). Chorion laeve and decidua vera synthesized predominantly 15-HETE at all times and placenta produced mainly 12-HETE. Trends existed for increased prostaglandin formation with labor by amnion, chorion laeve and decidua vera and for increased lipoxygenase product formation by chorion laeve, decidua vera and placenta. It is suggested that products of arachidonic acid metabolism by way of lipoxygenase and cyclooxygenase pathways play significant roles in the control of fetal and uteroplacental hemodynamics and the mechanism(s) of parturition.