The prostaglandin E2 (PGE2) receptor (EP1) is involved in triggering PGE2-mediated pain as well as neuronal survival and growth. SC-51322 is a selective EP1 antagonist that inhibits PGE2 signaling in a guinea pig ileum muscle strip assay with a pA2 value of 8.1 and demonstrates analgesic activity in a mouse writhing assay with an ED50 value of 0.9 mg/kg. It is pharmacologically similar to SC-51089, but does not release hydrazine, a known carcinogen to rats, as does SC-51089. SC-51322 potentiates the vasorelaxation of human pulmonary vein induced by PGE2 with an EC50 value of 7.75 μM.
