CP 544,326 is a potent agonist of E prostanoid (EP) receptor 2 (IC50s = 10 and 15 nM for human and rat EP2, respectively).1 It is selective for EP2 over other EP receptors (IC50s = >3,200 nM for EP1, EP3, and EP4) and a panel of 37 G protein-coupled receptors (≤30% inhibition at a concentration of 10 μM). CP 544,326 increases cAMP levels in HEK293 cells expressing human EP2 (EC50 = 2.8 nM). CP 544,326 has poor corneal permeability in an ex vivo rabbit corneal model. However, PF-04217329, a cell-permeable prodrug form of CP 544,326, reduces intraocular pressure in rabbit, canine, and marmoset models of glaucoma.
1.Prasanna, G., Carreiro, S., Anderson, S., et al.Effect of PF-04217329 a prodrug of a selective prostaglandin EP2 agonist on intraocular pressure in preclinical models of glaucomaExp. Eye Res.93(3)256-264(2011)