title: GW274150 and GW273629 are potent and highly selective inhibitors of inducible nitric oxide synthase in vitro and in vivo.
abstract: 1 GW274150 ([2-[(1-iminoethyl) amino]ethyl]-L-homocysteine) and GW273629 (3-[[2-[(1-iminoethyl)amino]ethyl]sulphonyl]-L-alanine) are potent, time-dependent, highly selective inhibitors of human inducible nitric oxide synthase (iNOS) vs endothelial NOS (eNOS) (>100-fold) or neuronal NOS (nNOS) (>80-fold). GW274150 and GW273629 are arginine competitive, NADPH-dependent inhibitors of human iNOS with steady state K(d) values of <40 and <90 nM, respectively. 2 GW274150 and GW273629 inhibited intracellular iNOS in J774 cells in a time-dependent manner, reaching IC(50) values of 0.2+/-0.04 and 1.3+/-0.16 microM, respectively. They were also acutely selective in intact rat tissues: GW274150 was >260-fold and 219-fold selective for iNOS against eNOS and nNOS, respectively, while GW273629 was >150-fold and 365-fold selective for iNOS against eNOS and nNOS, respectively. 3 The pharmacokinetic profile of GW274150 was biphasic in healthy rats and mice with a terminal half-life of approximately 6 h. That of GW273629 was also biphasic in rats, producing a terminal half-life of approximately 3 h. In mice however, elimination of GW273629 appeared monophasic and more rapid (approximately 10 min). Both compounds show a high oral bioavailability (>90%) in rats and mice. 4 GW274150 was effective in inhibiting LPS-induced plasma NO(x) levels in mice with an ED(50) of 3.2+/-0.7 mg kg(-1) after 14 h intraperitoneally (i.p.) and 3.8+/-1.5 mg kg(-1) after 14 h when administered orally. GW273629 showed shorter-lived effects on plasma NO(x) and an ED(50) of 9+/-2 mg kg(-1) after 2 h when administered i.p. 5 The effects of GW274150 and GW273629 in vivo were consistent with high selectivity for iNOS, as these inhibitors were of low potency against nNOS in the rat cerebellum and did not cause significant effects on blood pressure in instrumented mice.
authors.affiliation: Respiratory & Inflammation Centre of Excellence for Drug Discovery, GlaxoSmithKline Research, Medicines Research Centre, Gunnels Wood Road, Stevenage, Herts SG1 2NY, UK.
authors.forename: Wendy K
authors.initials: WK
authors.lastname: Alderton
authors.forename: Anthony D R
authors.initials: AD
authors.lastname: Angell
authors.forename: Caroline
authors.initials: C
authors.lastname: Craig
authors.forename: John
authors.initials: J
authors.lastname: Dawson
authors.forename: Edward
authors.initials: E
authors.lastname: Garvey
authors.forename: Salvador
authors.initials: S
authors.lastname: Moncada
authors.forename: Jayne
authors.initials: J
authors.lastname: Monkhouse
authors.forename: Daryl
authors.initials: D
authors.lastname: Rees
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Russell
authors.forename: Rachel J
authors.initials: RJ
authors.lastname: Russell
authors.forename: Sheila
authors.initials: S
authors.lastname: Schwartz
authors.forename: Neil
authors.initials: N
authors.lastname: Waslidge
authors.forename: Richard G
authors.initials: RG
authors.lastname: Knowles
mesh_terms: D000818:Animals; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D051381:Rats; D017208:Rats, Wistar; D018411:Spodoptera; D013440:Sulfides / Q000494:pharmacology*; D013450:Sulfones / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; C409003:GW 273629; D013440:Sulfides; D013450:Sulfones; C409004:GW 274150