– GW274150 (dihydrochloride) is a potent and selective inhibitor of human and rat inducible nitric oxide synthase (iNOS), exhibiting oral activity and NADPH-dependence with an IC50 of 2.19 μM and Kd of 40 nM for human iNOS, and an ED50 of 1.15 μM for rat iNOS. It demonstrates reduced effectiveness against endothelial NOS (eNOS) and neuronal NOS (nNOS) in both species, and has shown protective effects in acute lung injury inflammation models [1] [2] [3].