Prostaglandin E2 catabolism in the spinal nerve roots of the cat

Catabolism of prostaglandin (PG) E2 was studied in homogenates of spinal cord and spinal nerve roots of the cat. Spinal roots enzymatically converted PGE2 to a product (metabolite I) with the chromatographic mobility of 15-keto-PGE2. Little metabolic degradation occurred in the spinal cord; however, incubation of PGE2 with combined spinal cord and nerve root tissue yielded a second metabolite (metabolite II) in addition to metabolite I. Metabolite II was identified as 15-keto-13, 14-dihydro-PGE2. These results prove that spinal nerve roots, unlike the spinal cord, contain 15-hydroxyprostaglandin dehydrogenase (15-PGDH) which is the major and rate-limiting enzyme in the inactivation of prostaglandins. The location and functional significance of 15-PGDH in peripheral nerves remain to be elucidated.