RESUMEN
CONTEXT: VX-702 is a novel p38 mitogen-activated protein kinase inhibitor being developed to treat rheumatoid arthritis. OBJECTIVE: To characterize the renal excretion profile of VX-702 using the isolated perfused rat kidney (IPRK) model. METHODS: Studies were performed to assess the dose linearity of VX-702 excretion and to evaluate the effect of inhibitors of organic anion (probenecid) and organic cation (cimetidine) transport systems on VX-702 disposition. VX-702 excretion was studied over a range of doses targeting concentrations between 100 and 600 ng/mL. VX-702 (600 ng/mL) was also co-perfused with probenecid (1 mM) and cimetidine (2 mM). The results were compared to parallel experiments performed with methotrexate (MTX). RESULTS: VX-702 excretion was linear over the range of doses studied, and clearance data were consistent with net reabsorption by the kidney. Transport inhibition studies indicate that VX-702 is not a substrate for renal organic anion and organic cation transport systems. MTX (500 ng/mL) also displayed net reabsorption in the IPRK, but secretory transport was inhibited upon co-administration with probenecid. This finding is consistent with previous IPRK studies that demonstrated inhibitory effects of NSAIDS on MTX excretion. CONCLUSION: Overall, this study suggests that a renal drug-drug interaction between VX-702 and MTX would be unlikely if these medications were co-administered.
Asunto(s)
Antirreumáticos/metabolismo , Inhibidores Enzimáticos/metabolismo , Riñón/metabolismo , Metotrexato/metabolismo , Compuestos de Fenilurea/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Algoritmos , Animales , Cimetidina/farmacología , Interacciones Farmacológicas , Inhibidores Enzimáticos/análisis , Inhibidores Enzimáticos/química , Tasa de Filtración Glomerular/efectos de los fármacos , Factores Inmunológicos/metabolismo , Riñón/efectos de los fármacos , Cinética , Masculino , Metotrexato/análisis , Metotrexato/química , Transportadores de Anión Orgánico/antagonistas & inhibidores , Transportadores de Anión Orgánico/fisiología , Proteínas de Transporte de Catión Orgánico/antagonistas & inhibidores , Proteínas de Transporte de Catión Orgánico/fisiología , Concentración Osmolar , Perfusión , Compuestos de Fenilurea/análisis , Compuestos de Fenilurea/química , Probenecid/farmacología , Ratas , Ratas Sprague-Dawley , UltrafiltraciónRESUMEN
In the search for a selective adenosine A1 receptor antagonist with greater aqueous solubility than the compounds currently in clinical trials as diuretics, a series of 1,4-substituted 8-cyclohexyl and 8-bicyclo[2.2.2]octylxanthines were investigated. The binding affinities of a variety of cyclohexyl and bicyclo[2.2.2]octylxanthines for the rat and human adenosine A1, A2A, A2B, and A3 receptors are presented. Bicyclo[2.2.2]octylxanthine 16 exhibited good pharmaceutical properties and in vivo activity in a rat diuresis model (ED50=0.3 mg/kg po). Optimization of the bridgehead substituent led to propionic acid 29 (BG9928), which retained high potency (hA1, Ki=7 nM) and selectivity for the adenosine A1 receptor (915-fold versus adenosine A2A receptor; 12-fold versus adenosine A2B receptor) with improved oral efficacy in the rat diuresis model (ED50=0.01 mg/kg) as well as high oral bioavailability in rat, dog, and cynomolgus monkey.
Asunto(s)
Antagonistas del Receptor de Adenosina A1 , Xantinas/síntesis química , Administración Oral , Animales , Disponibilidad Biológica , Encéfalo/metabolismo , Línea Celular , Cricetinae , Cricetulus , Diuresis/efectos de los fármacos , Perros , Atrios Cardíacos/efectos de los fármacos , Humanos , Técnicas In Vitro , Macaca fascicularis , Masculino , Ensayo de Unión Radioligante , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad , Xantinas/farmacocinética , Xantinas/farmacologíaRESUMEN
In vitro and in animals, I is a potent and specific peptidomimetic for the potential treatment of airway inflammation in the pathogenesis of asthma. Preclinical studies indicated extensive conversion of I to an active metabolite II, and thus, a very sensitive assay for I and II was needed to support an inhalation ascending-dose study in man. The LC/MS/MS plasma/urine assay method (1.0 ml of sample) involves the following: liquid-liquid extraction of acidified plasma into pentane-ethyl acetate (90:10 v/v); evaporation of the organic extract, reconstitution into methanol; addition of water to the methanolic extract and freezing. After thawing, the extract is centrifuged and the clear supernatant injected for chromatography. Extract is chromatographed on a YMC ODS-AM column (50 x 2.0 mm). For detection, a Sciex 365 LC/MS/MS with an electrospray inlet and used in the positive ion, multiple reaction monitoring mode was used to monitor precursor-->fragment ions of m/z 709-->594 for I and m/z 513-->380 for II. The plasma assay was linear over the concentration range of 0.1-100 ng/ml in plasma for I and II. Accuracy and precision for I ranged from 97.9 to 102.1% of nominal with a 0.84-10.65% CV; similarly for II, 98.0-101.7% and 1.39-9.28% CV, respectively. Extraction recovery averaged 63.7% for I and 64.9% for II. This general assay methodology may be applied to assay small acidic peptides and peptidomimetics from biological fluids by LC/MS/MS.