Metabolism of prostaglandins within the pregnant uterus.

The metabolism of E and F prostaglandins has been studied in both fetal and maternal tissues obtained from the pregnant human uterus. Both 15-hydroxyprostaglandin dehydrogenase and 13,14-prostaglandin reductase are shown to be widely distributed in these tissues. Comparison of the levels of enzyme activity in different tissues demonstrates that the greatest metabolism of prostaglandins takes place in the membranes and placenta and that there is much less in the myometrium and the decidua. The lowest enzyme activity was found in the umbilical cord, and no metabolism could be demonstrated in amniotic fluid or in umbilical venous blood. The significance of these findings is discussed.