Synthesis of 12-hydroxyeicosatetraenoic acid by human endometrium and decidua

In order to clarify the possible involvement of lipoxygenase metabolites of arachidonic acid (AA) in implantation, monohydroxylic acid production was examined using human endometrium and decidua in early pregnancy. As 14C-AA was mainly converted to 12-hydroxyeicosatetraenoic acid (12-HETE) as well as prostaglandins (PGs) by the microsomal fraction of the endometrium, a subsequent study was carried out on the endometrium (at various stages) and decidua in early pregnancy using tissue incubation and high performance liquid chromatography (HPLC) analysis for 12-HETE. The amounts of 12-HETE released into the culture medium by proliferative and secretory endometrium were 165.1 +/- 123.4 (ng/mg.protein/24 h, mean +/- SD) and 502.3 +/- 127.2, respectively, whereas, decidua produced a smaller amount of 12-HETE that declined as gestation progressed. This lipoxygenase product as well as PGs might have a role in implantation.