Lipoxygenase gene expression in baboon intrauterine tissues in late pregnancy and parturition.

Myometrium (upper and lower segment), cervix, chorion and decidua were obtained at the time of Caesarean hysterectomy in 15 baboons, 10 at varying gestational ages prior to the onset of labour in the last trimester of pregnancy, and five in spontaneous labour at term. Expression of currently recognized human lipoxygenase (LOX) genes was determined using Northern blot analysis relative to each of three housekeeping genes. Signals of similar size to human 5-LOX and human platelet 12-LOX genes were detected in all tissues. Expression of 5-LOX mRNA in the cervix decreased with advancing gestational age. In decidua, expression of 5-LOX mRNA was higher in tissues from animals in labour (compared to those not in labour), whereas in chorion, its expression was lower in tissues from animals in labour. Expression of the platelet 12-LOX gene decreased in chorion with advancing gestational age, and in cervix was lower in tissues from animals in labour. We postulate that the variation in expression of LOX genes may play a role in the onset or promotion of parturition in the baboon.