GKT137831 is a novel, specific dual NADPH oxidase (NOX1/4) inhibitor. GKT137831 has potency both on human Nox4 (K_i=140±40 nM) and human Nox1 (K_i=110±30 nM) and is found 15-fold less potent on Nox2 (K_i=1750±700 nM) and 3-fold less potent on Nox5 (K_i=410±100 nM).

Ki: 140±40 nM (Nox4), 110±30 nM (Nox1)^[1]

GKT137831 is a potent Nox4 inhibitor (K_i=120±30 nM) with an affinity similar to the irreversible and unspecific flavoprotein inhibitor Diphenyliodonium (DPI; K_i=70±10 nM)^[1]. Administration of GKT137831 throughout the 72-hour period of normoxia or hypoxia exposure attenuates HPASMC proliferation under normoxic conditions at the 20 μM concentration but had no effect on proliferation in normoxic HPAECs. In the prevention paradigm, GKT137831 attenuates hypoxia-induced HPASMC and HPAEC proliferation at 5 and 20 μM. Complementary assays of cell proliferation measuring the expression of PCNA or manual cell counting confirmed that GKT137831 attenuates hypoxia-induced pulmonary vascular cell proliferation^[2].

During the last half of CCl₄ injections, some mice are treated with GKT137831 daily. CCl₄-induced liver fibrosis is more pronounced in SOD1mu compared to WT mice. Liver fibrosis in both SOD1mu and WT mice is attenuated by GKT137831 treatment. The increased hepatic α-SMA expression is markedly decreased in SOD1mu mice treated with GKT137831, to a level similar to that of WT mice given the NOX1/4 inhibitor^[1].

• [1]. Aoyama T, et al. Nicotinamide adenine dinucleotide phosphate oxidase in experimental liver fibrosis: GKT137831 as a novel potential therapeutic agent. Hepatology. 2012 Dec;56(6):2316-27.

  [2]. Green DE, et al. The Nox4 inhibitor GKT137831 attenuates hypoxia-induced pulmonary vascular cell proliferation. Am J Respir Cell Mol Biol. 2012 Nov;47(5):718-26.

GKT137831 is dissolved in DMSO and stored, and then diluted with appropriate media (DMSO 1%) before use^[2].

Monolayers of HPAECs and HPASMCs are propagated in culture and placed in normoxic (21% O₂, 5% CO₂) or hypoxic (1% O₂, 5% CO₂) conditions for 72 hours. GKT137831 (0.1-20 μM), or vehicle (1% DMSO) are added to the culture medium at the onset (prevention regimen) or during the last 24 hours (intervention regimen) of a 72-hour hypoxia exposure regimen^[2]. MCE has not independently confirmed the accuracy of these methods. They are for reference only.

GKT137831 is prepared in corn oil^[1].

Mice^[1]
Specific pathogen-free, wild-type (WT) C57BL/6J mice are used. For the carbon tetrachloride (CCl₄) model of liver fibrosis, 6 week old male mice are injected intraperitoneally with CCl₄, which is diluted 1:3 in corn oil, or with vehicle (corn oil) at a dose of 0.5 μL/g of body weight twice a week for a total of 12 injections. During the last half of CCl₄ treatment, mice are treated with 60 mg/kg of the NOX1/4 inhibitor GKT137831 or vehicle by intragastric injection daily. Mice are sacrificed 48 hours after the last CCl₄ injection. For the bile duct ligation (BDL) model, 6 week old male mice are anesthetized. After laparotomy, the common bile duct is ligated twice and the abdomen closed. The sham operation is performed similarly without BDL. From 11 days after operation, mice are treated with 60 mg/kg of the NOX1/4 inhibitor GKT137831 or vehicle by daily intragastric lavage. Mice are sacrificed 21 days after operation. Serum levels of alanine aminotransferase (ALT) are measured with a commercial kit. MCE has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Aoyama T, et al. Nicotinamide adenine dinucleotide phosphate oxidase in experimental liver fibrosis: GKT137831 as a novel potential therapeutic agent. Hepatology. 2012 Dec;56(6):2316-27.

  [2]. Green DE, et al. The Nox4 inhibitor GKT137831 attenuates hypoxia-induced pulmonary vascular cell proliferation. Am J Respir Cell Mol Biol. 2012 Nov;47(5):718-26.

394.85

C₂₁H₁₉ClN₄O₂

1218942-37-0

Room temperature in continental US; may vary elsewhere

DMSO: ≥ 37 mg/mL

* "<1 mg/ml"="" means="" slightly="" soluble="" or="" insoluble.="" "≥"="" means="" soluble,="" but="" saturation="">