[Study on PGDH activity in human term placenta--relationship between PGDH activities and perinatal factors]

The high activity of 15-hydroxyprostaglandin dehydrogenase (PGDH) which catalyzes the first step in prostaglandin metabolism has been demonstrated in the human placenta. To investigate the role of placental PGDH (p-PGDH) in the perinatal period, PGDH activity was measured in 167 placentas of gestational ages 37 to 41 weeks. The activity was expressed as n mole/min/non heme protein of 15-keto-PGE2 which was produced by incubation of PGE2 and placental homogenate supernatant. The following data were obtained. p-PGDH activity was significantly lower at the 40 weeks of gestation than at other weeks. There was no difference in placental PGDH activity between cesarean section and vaginal delivery, and between the periods before and after onset labor of cesarean section. p-PGDH activity in the PGs administered group was higher than that in the non PGs group. p-PGDH activity of a male fetus was higher than that of a female. This suggests that p-PGDH activity is under the control of hormones. No relationship was observed between p-PGDH activity and other perinatal factors such as toxemia of pregnancy, parity, Apgar score, birth weight, placental weight, blood loss, and duration of labor.