Prostaglandin biosynthesis and catabolism in the developing fetal sheep kidney.

The enzymatic capacity to form and degrade prostaglandins was studied in kindeys from fetal sheep (gestational ages 40,44,49,77,79,116 and 140 days). The prostaglandin system was detectable at all ages. Only prostaglandin F2alpha was formed by renal homogenates at 40 and 44 days gestation; prostaglandin E2 was first formed by the 77 day kidney and became the major prostaglandin by 116 days (3 fold relative to prostaglandin F2alpha). Prostaglandin catabolism took place via the PG 15-hydroxy dehydrogenase and PG 13-reductase pathways. Catabolism was first detected at 40 days gestation and rose with age to an activity (15-PGDH) approximately 80 ng/min/mg protein in the term kidney. Only PG 15-hydroxydehydrogenase activity was detected at 40 days gestation, but PG 13-reducatse activity became evident by 116 days and persisted until term. As with fetal sheep lungs (see preceding publication) PG 13-reductase activity was saturated quickly. These results confirm our observations with other tissues that prostaglandin catabolism is variable during ontogeny.