An NADP-linked prostacyclin dehydrogenase in rabbit kidney

An NADP-linked 15-hydroxyprostaglandin dehydrogenase specific for prostacyclin was purified 1,300-fold from rabbit kidney. Prostaglandins E2, F2 alpha, and 6-keto PGF1 alpha and thromboxane B2 were oxidized by the purified enzyme with rates of reaction less than 4% that of PGI2. Unlike other rabbit kidney NADP-linked 15-hydroxyprostaglandin dehydrogenases, this enzyme catalyzes oxido-reduction more rapidly at the 15- position than at the 9- position and does not utilize NAD as a cofactor. It has a molecular weight of 62,000 and migrates on polyacrylamide disc gel electrophoresis as a single diffuse band. The reaction product was identified by thin-layer chromatography as 6,15-diketo PGF1 alpha. Prostacyclin dehydrogenase is the first 15-hydroxyprostaglandin dehydrogenase described which is specific for the metabolism of prostacyclin.