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) (4100-fold) or neuronal NOS (nNOS) (480-fold). GW274150 and GW273629 are arginine competitive, NADPH-dependent inhibitors of human iNOS with steady state K d values of o40 and o90 nM, respectively. 2 GW274150 and GW273629 inhibited intracellular iNOS in J774 cells in a time-dependent manner, reaching IC 50 values of 0.270.04 and 1.370.16 mM, respectively. They were also acutely selective in intact rat tissues: GW274150 was 4260-fold and 219-fold selective for iNOS against eNOS and nNOS, respectively, while GW273629 was 4150-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 B6 h. That of GW273629 was also biphasic in rats, producing a terminal half-life of B3 h. In mice however, elimination of GW273629 appeared monophasic and more rapid (B10 min). Both compounds show a high oral bioavailability (490%) in rats and mice. 4 GW274150 was effective in inhibiting LPS-induced plasma NO x levels in mice with an ED 50 of 3.270.7 mg kg À1 after 14 h intraperitoneally (i.p.) and 3.871.5 mg kg À1 after 14 h when administered orally. GW273629 showed shorter-lived effects on plasma NO x and an ED 50 of 972 mg kg À1 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.

In Vivo Characterization of the Novel Imidazopyridine BYK191023 [2-[2-(4-Methoxy-pyridin-2-yl)-ethyl]-3H-imidazo[4,5-b]pyridine], a Potent and Highly Selective Inhibitor of Inducible Nitric-Oxide Synthase

“…3). These results confirm data from infusion studies with the selective iNOS inhibitors 1400W (Wray et al, 1998;Cheng et al, 2003) and GW273629 (Alderton et al, 2005) and corroborate the view that excessive NO production by iNOS is a major mechanism underlying the development of hypotension in the course of systemic inflammation. According to our data, selective inhibition of iNOS by BYK191023 without interfering with constitutively expressed e/nNOS activity should be sufficient for the desired therapeutic effect on macrocirculation.…”

Tumor microenvironment-based feed-forward regulation of NOS2 in breast cancer progression

“…NOS2 activity was inhibited by the addition of 1 mM AG (Sigma), and cellular effects of NO were independently evaluated by adding the NO donor DETA/NO (T 1/2 = 20 h at 37°C) at various concentrations (Larry Keefer, National Cancer Institute-Frederick). We selected AG as the primary tool in our studies because of its previous use in clinical trials, its well established oral administration, and because the other common NOS2 inhibitor, 1400W, has shown toxic effects at higher doses (37).…”

The Novel Imidazopyridine 2-[2-(4-Methoxy-pyridin-2-yl)-ethyl]-3H-imidazo[4,5-b]pyridine (BYK191023) Is a Highly Selective Inhibitor of the Inducible Nitric-Oxide Synthase

“…Very few highly selective iNOS inhibitors have been described in the literature, but none reached the clinic. Clinical development of 1400W was discontinued because of toxicity issues (Alderton et al, 2005). Inhibitors of iNOS dimerization only act at the monomeric level of iNOS (McMillan et al, 2000) and are not suited for inhibition of already expressed and active iNOS.…”

“…In fact, only very few selective iNOS inhibitors are available for research, and none has reached approved clinical application (Mete and Connolly, 2003). Data from selective inhibitors available such as 1400W (GlaxoSmithKline, Uxbridge, Middlesex, UK) (Garvey et al, 1997), GW274150 and GW273629 (GlaxoSmithKline) (Young et al, 2000;Alderton et al, 2005), AR-C102222 (AstraZeneca Pharmaceuticals LP, Wilmington, DE) (Beaton et al, 2001;Tinker et al, 2003), ONO1714 (Ono Pharmaceuticals, Osaka, Japan) (Nishina et al, 2001), L-arginine derivatives (SC-51 or L-NIL) (Pfizer Central Research, Sandwich, Kent, UK) (Hansel et al, 2003), and the dimerization inhibitor BBS-1 (Berlex Laboratories, Wayne, NJ) (McMillan et al, 2000;Blasko et al, 2002;Habisch et al, 2003) show promising results in animal models of sepsis, lung inflammation, arthritis, and autoimmune diabetes. Development of some of these compounds into the clinic has been stopped because of toxicity issues (1400W) (Alderton et al, 2005).…”