Prostaglandins are rapidly inactivated in vivo by the action of 15-hydroxy prostaglandin dehydrogenase (15-hydroxy PGDH). This enzyme oxidizes the 15-hydroxyl group and hydrogenates the 13,14-double bond, producing 13,14-dihydro-15 keto metabolites with greatly reduced biological activity. CAY10397 is a selective inhibitor of 15-hydroxy PGDH with an IC50 of approximately 10 μM. CAY10397 acts to prolong the lifetime and activity of endogenously produced prostaglandins both in cell culture and in vivo.