Objective: The aim of this study was to investigate whether any changes occurred at term before and with labor in the 15-hydroxyprostaglandin dehydrogenase messenger ribonucleic acid level and in the 15-hydroxyprostaglandin dehydrogenase activity in cultured chorionic and villous trophoblast cells and in chorionic explants.
Study design: Twelve placentas (labor group [vaginal delivery], n = 6; nonlabor group [elective cesarean delivery], n = 6) were collected. Chorionic trophoblast and villous trophoblast cells and chorionic disks were obtained, cultured, and incubated with 282-nmol/L prostaglandin F(2)(alpha). Medium was collected to measure the 13,14-dihydro-15-keto metabolite of prostaglandin F(2)(alpha), and the cells and disks were snap-frozen to quantify 15-hydroxyprostaglandin dehydrogenase messenger ribonucleic acid expression by Northern blot analysis.
Results: The formation of the 13,14-dihydro-15-keto metabolite of prostaglandin F(2)(alpha) was significantly lower in the labor group than in the nonlabor group for both sets of cultured cells and for chorionic explants. 15-Hydroxyprostaglandin dehydrogenase messenger ribonucleic acid expression was lower in the chorionic trophoblast cells and chorionic disks of the labor group than those of the nonlabor group. However, the 15-hydroxyprostaglandin dehydrogenase messenger ribonucleic acid level in the villous trophoblast cells did not differ between the labor and nonlabor groups.
Conclusion: Prostaglandin metabolic activity in the chorion is reduced significantly at the time of labor.