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Reinen, J. (author), Nematollahi, L. (author), Fidder, A. (author), Vermeulen, N.P.E. (author), Noort, D. (author), Commandeur, J.N.M. (author)Tri-ortho-cresyl phosphate (ToCP) is a multipurpose organophosphorus compound that is neurotoxic and suspected to be involved in aerotoxic syndrome in humans. It has been reported that not ToCP itself but a metabolite of ToCP, namely, 2-(ortho-cresyl)-4H-1,2,3-benzodioxaphosphoran-2-one (CBDP), may be responsible for this effect as it can...article 2015
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Treijtel, N. (author), Eijkeren, J.C.H.v. (author), Nijmeijer, S. (author), van der Greef de - Sandt, I.C.J. (author), Freidig, A.P. (author), TNO Kwaliteit van Leven (author)The metabolism and active transport of ritonavir and saquinavir were studied using sandwich-cultured rat hepatoyctes and rat liver microsomes. For ritonavir four comparable metabolites were observed in the sandwich-culture and in microsomes. For saquinavir eight metabolites were observed in sandwich-culture and 14 different metabolites in...article 2009
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Jeurissen, S.M.F. (author), Punt, A. (author), Boersma, M.G. (author), Bogaards, J.J.P. (author), Fiamegos, Y.C. (author), Schilter, B. (author), van Bladeren, P.J. (author), Cnubben, N.H.P. (author), Rietjens, I.M.C.M. (author), TNO Kwaliteit van Leven (author)Human cytochrome P450 enzymes involved in the bioactivation of estragole to its proximate carcinogen 1′-hydroxyestragole were identified and compared to the enzymes of importance for 1′-hydroxylation of the related alkenylbenzenes methyleugenol and safrole. Incubations with Supersomes revealed that all enzymes tested, except P450 2C8, are...article 2007
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Jeurissen, S.M.F. (author), Bogaards, J.J.P. (author), Boersma, M.G. (author), ter Horst, J.P.F. (author), Awad, H.M. (author), Fiamegos, Y.C. (author), van Beek, T.A. (author), Alink, G.M. (author), Sudhölter, E.J.R. (author), Cnubben, N.H.P. (author), Rietjens, I.M.C.M. (author), TNO Kwaliteit van Leven (author)In vitro studies were performed to elucidate the human cytochrome P450 enzymes involved in the bioactivation of methyleugenol to its proximate carcinogen 1′-hydroxymethyleugenol. Incubations with Supersomes, expressing individual P450 enzymes to a high level, revealed that P450 1A2, 2A6, 2C9, 2C19, and 2D6 are intrinsically able to 1′...article 2006
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Parnham, M.J. (author), Bogaards, J.J.P. (author), Schrander, F. (author), Schut, M.W. (author), Orešković, K. (author), Mildner, B. (author), TNO Kwaliteit van Leven (author)PLD-118 is a novel, oral antifungal drug, under development for the treatment of Candida infections. Possible metabolism of PLD-118 by rat, dog and human S9 liver homogenates and inhibition of human cytochrome P450 (CYP) enzymes were investigated. PLD-118 (10 and 100 μm) incubated for 0-60 min with S9 fractions and NADPH was determined by HPLC,...article 2005
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Kohli, E. (author), Gaspari, M. (author), Raj, H.G. (author), Parmar, V.S. (author), Sharma, S.K. (author), van der Greef, J. (author), Kumari, R. (author), Gupta, G. (author), Khurana, P. (author), Tyagi, Y.K. (author), Watterson, A.C. (author), Olsen, C.E. (author), TNO Voeding (author)The purification and characterization of the buffalo liver microsomal transacetylase (TAase) catalyzing the transfer of acetyl groups from a model acetoxy drug: 7,8-diacetoxy-4-methylcoumarin (DAMC) to GST3-3 has been described here. The enzyme was routinely assayed using DAMC and cytosolic GST as the substrates and was partially purified from...article 2004
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Price, R.J. (author), Scott, M.P. (author), Walters, D.G. (author), Stierum, R.H. (author), Groten, J.P. (author), Meredith, C. (author), Lake, B.G. (author), TNO Voeding (author)The effect of thiabendazole (TB) on some rat hepatic xenobiotic metabolising enzymes has been investigated. Male Sprague-Dawley rats were fed control diet or diets containing 102-5188 ppm TB for 28 days. As a positive control for induction of hepatic xenobiotic metabolism, rats were also fed diets containing 1457 and 10,155 ppm butylated...article 2004
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Renwick, A.B. (author), Ball, S.E. (author), Tredger, J.M. (author), Price, R.J. (author), Walters, D.G. (author), Kao, J. (author), Scatina, J.A. (author), Lake, B.G. (author), TNO Voeding (author)The effect of cimetidine on the metabolism of zaleplon (ZAL) in human liver subcellular fractions and precision-cut liver slices was investigated. 2. ZAL was metabolized to a number of products including 5-oxo-ZAL (M2), which is known to be formed by aldehyde oxidase, N-desethyl-ZAL (DZAL), which is known to be formed by CYP3A forms, and N...article 2002
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Bogaards, J.J.P. (author), Hissink, E.M. (author), Briggs, M. (author), Weaver, R. (author), Jochemsen, R. (author), Jackson, P. (author), Bertrand, M. (author), van Bladeren, P. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)A strategy is presented to predict interindividual variation in drug plasma levels in vivo by the use of physiologically based pharmacokinetic modeling and human in vitro metabolic parameters, obtained through the combined use of microsomes containing single cytochrome P450 enzymes and a human liver microsome bank. The strategy, applied to the...article 2000
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van Puymbroeck, M. (author), Kuilman, M.E.M. (author), Maas, R.F.M. (author), Witkamp, R.F. (author), Leyssens, L. (author), van Miert, A.S.J.P.A.M. (author), Hendriks, L. (author), van der Zande, D.J.M. (author), Adriaensens, P. (author), Jacobs, M.-P. (author), Raus, J. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)The metabolism of the illegal growth promoter ethylestrenol (EES) was evaluated in bovine liver cells and subcellular fractions of bovine liver preparations. Incubations with bovine microsomal preparations revealed that EES is extensively biotransformed into norethandrolone (NE), another illegal growth promoter. Furthermore, incubations of...article 1999
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Bessems, J.G.M. (author), de Groot, M.J. (author), Baede, E.J. (author), te Koppele, J.M. (author), Vermeulen, N.P.E. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)1. The formation of free radicals during enzyme catalysed oxidation of eight 3,5-disubstituted analogues of paracetamol (PAR) has been studied. A simple peroxidase system as well as cytochrome P450-containing systems were used. Radicals were detected by electron spin resonance (ESR) on incubation of PAR and 3,5-diCH3-, 3,5-diC2H5-, 3,5-ditC4H9-,...article 1998
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Centraal Instituut voor Voedingsonderzoek TNO TNO Voeding (author), van Puymbroeck, M. (author), Kuilman, M.E.M. (author), Maas, R.F.M. (author), Witkamp, R.F. (author), Leyssens, L. (author), van der Zande, D.J.M. (author), Gelan, J. (author), Raus, J. (author)17alpha-Boldenone (17alpha-BOL) and/or 17beta-boldenone (17beta-BOL) appear occasionally in fecal matter of cattle. In addition to 17alpha-BOL, a whole array of boldenone related substances can be found in the same samples. In vitro experiments with microsomal liver preparations and isolated hepatocytes combined with the excretion profiles found...article 1998
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Centraal Instituut voor Voedingsonderzoek TNO TNO Voeding (author), van Puymbroeck, M. (author), Kuilman, M.E.M. (author), Maas, R.F.M. (author), Witkamp, R.F. (author), Leyssens, T. (author), van der Zande, D.J.M. (author), Gelan, J. (author), Raus, J. (author)Current veterinary residue analysis mainly focuses on the monitoring of residues of the administered parent compound. However, it is possible that larger amounts of metabolites are excreted and that they can have a prolonged excretion period. In order to unravel specific metabolic steps and to identify possible biological markers, two in vitro...article 1998
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Comparison of five incubation systems for rat liver slices using functional and viability parametersOlinga, P. (author), Groen, K. (author), Hof, I.H. (author), de Kanter, R. (author), Koster, H.J. (author), Leeman, W.R. (author), Rutten, A.A.J.J.L. (author), van Twillert, K. (author), Groothuis, G.M.M. (author), Centraal Instituut voor Voedingsonderzoek TNO TNO Voeding (author)Precision-cut liver slices are presently used for various research objects, e.g. to study metabolism, transport, and toxicity of xenobiotics. Various incubation systems are presently employed, but a systematic comparison between these incubation systems with respect to preservation of slice function has not been performed yet. Therefore, we...article 1997
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Dahl, M.L. (author), Voortman, G. (author), Alm, C. (author), Elwin, C.E. (author), Delbressine, L. (author), Vos, R. (author), Bogaards, J.J.P. (author), Bertilsson, L. (author), Centraal Instituut voor Voedingsonderzoek TNO TNO Voeding (author)The novel antidepressant mirtazapine is a racemate with both noradrenergic and serotonergic potentiating effects. In vitro metabolism of racemic mirtazapine was studied in (a) microsomes from cells expressing different cytochrome P450 (CYP) enzymes and (b) human liver microsomes from 10 subjects and compared with the rate of metabolism of 4...article 1997
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TNO Voeding Centraal Instituut voor Voedingsonderzoek TNO (author), Hissink, A.M. (author), Oudshoorn, M.J. (author), van Ommen, B. (author), van Bladeren, P.J. (author)Our goal was to characterize possible species and strain differences in the hepatic microsomal biotransformation of 1,4-dichlorobenzene (1,4-DCB). Experiments compared extent of labeled 1,4-DCB conversion to oxidized metabolites, glutathione conjugates, and covalently bound metabolites by hepatic microsomes from humans, from male B6C3F1 mice,...article 1997
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TNO Voeding Centraal Instituut voor Voedingsonderzoek TNO (author), Hissink, A.M. (author), van Ommen, B. (author), Krüse, J. (author), van Bladeren, P.J. (author)A physiologically based pharmacokinetic (PB-PK) model was developed for 1,2-dichlorobenzene (1,2-DCB) for the rat. This model was adjusted for the human situation, using human in vitro parameters, including a V(max) and K(m) determined with human microsomes. For comparison, the V(max) and K(m) values from the rat were scaled allometrically to...article 1997
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Bessems, J.G.M. (author), te Koppele, J.M. (author), van Dijk, P.A. (author), van Stee, L.L.P. (author), Commandeur, J.N.M. (author), Vermeulen, N.P.E. (author), Leiden/Amsterdam Ctr. for Drug Res., Division of Molecular Toxicology, Vrije Universiteit, De Boelelaan 1083, 1081 HV Amsterdam, Netherlands Dept. Vasc. Connective Tissue Res TNO Preventie en Gezondheid (author)1. The cytochrome P450-dependent binding of paracetamol and a series of 3,5-disubstituted paracetamol analogues (R = -F, -Cl, -Br, -I, -C(H)3, -C2H5, -iC3H7) have been determined with β-naphthoflavone (βNF)-induced rat liver microsomes and produced reverse type I spectral changes. K(s,app) varied from 0.14 mM for 3,5-diiC3H7-paracetamol to 2.8...article 1996
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Hissink, A.M. (author), Oudshoorn, M.J. (author), van Ommen, B. (author), Haenen, G.R.M.M. (author), van Bladeren, P.J. (author)The oxidative biotransformation of 1, 2-dichlorobenzene (1, 2-DCB) was investigated using hepatic microsomes from male Wistar, Fischer-344 and Sprague-Dawley (SD) rats, phenobarbital (PB)- and isoniazid (ISO) pretreated male Wistar rats and from man. In addition, microsomes from cell lines selectively expressing one cytochrome P450 (P4502E1, 1A1...article 1996
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Morse, D.C. (author), Plug, A. (author), Wesseling, W. (author), van den Berg, K.J. (author), Brouwer, A. (author), TNO Voeding (author)Pregnant Wistar WU rats were exposed to 0, 5, and 25 mg of the commercial polychlorinated biphenyl (PCB) mixture Aroclor 1254 per kilogram of body weight on Days 10 to 16 of gestation. Pregnant rats were sacrificed on Gestation Day 20 to observe effects on fetal body and brain weights. Male and female offspring were sacrificed on Postnatal Days...article 1996
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