GW274150 (dihydrochloride) is a potent, selective, orally active and NADPH-dependent inhibitor of human inducible nitric oxide synthase ( iNOS ) ( IC 50 =2.19 μM; K d =40 nM) and rat iNOS ( ED 50 =1.15 μM). GW274150 (dihydrochloride) displays less potency for both humans or rats endothelial NOS ( eNOS ) and neuronal NOS ( nNOS ). GW274150 (dihydrochloride) exerts a protective role in an acute model of lung injury inflammation.