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Direct cell-to-cell contact between Kupffer cells and hepatocytes augments endotoxin-induced hepatic injury

Hoebe, K.H.N. (author), Witkamp, R.F. (author), Fink-Gremmels, J. (author), van Miert, A.S.J.P.A.M. (author), Monshouwer, M. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

This study focuses on the importance of direct contact between Kupffer cells (KCs) and hepatocytes (HCs) during the hepatic inflammatory response using an in vitro approach. The lipopolysaccharide (LPS)-induced inflammatory response in monocultures of porcine HCs and KCs were compared with cocultures prepared either with direct contact between...

article 2001

document

Differential effects of pentoxifylline on the hepatic inflammatory response in porcine liver cell cultures increase in inducible nitric oxide synthase expression

Centraal Instituut voor Voedingsonderzoek TNO (author), Hoebe, K.H.N (author), Gonzalez-Ramon, N. (author), Nijmeijer, S.M. (author), Witkamp, R.F. (author), van Leengoed, L.A.M.G (author), van Miert, A.S.J.P.A.M (author), Monshouwer, M. (author)

Pentoxifylline (PTX) has been shown to exert hepatoprotective effects in various liver injury models. However, little information is available about the effect of PTX on the hepatic acute phase response. In the present study, the effect of PTX on a lipopolysaccharide (LPS)-induced acute phase response in primary porcine liver cell cultures was...

article 2001

document

Stereoselectivity at the B2-adrenoceptor on macrophages is a major determinant of the anti-inflammatory effects of B2-agonists

Izeboud, C.A. (author), Vermeulen, R.M. (author), Zwart, A. (author), Vos, H.P. (author), van Miert, A.S.J.P.A.M. (author), Witkamp, R.F. (author)

Previous research has shown that β-adrenoceptor (β-AR) agonists have potent anti-inflammatory capabilities, e.g. represented by suppression of release of the proinflammatory cytokines. Aim of this research was to determine whether the effects of β-agonists on LPS-induced TNFα and IL-10 release are influenced by their different stereochemistry....

article 2000

document

Cocultures of porcine hepatocytes and kupffer cells as an improved in vitro model for the study of hepatotoxic compounds

TNO Pharma (author), Hoebe, K.H.N. (author), Monshouwer, M. (author), Witkamp, R.F. (author), Fink-Gremmels, J. (author), van Miert, A.S.J.P.A.M. (author)

article 2000

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The β-adrenoceptor agonist clenbuterol is a potent inhibitor of the LPS-induced production of TNF-α and IL-6 in vitro and in vivo

Izeboud, C.A. (author), Monshouwer, M. (author), van Miert, A.S.J.P.A.M. (author), Witkamp, R.F. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

Objective and Design: To investigate the suppressive effects of the β-agonist clenbuterol on the release of TNF-α and IL-6 in a lipopolysaccharide (LPS)-model of inflammation, both in vitro and in vivo. Material and Subjects: Human U-937 cell line (monocyte-derived macrophages), and male Wistar rats (200-250 g). Treatment: U-937 macrophages were...

article 1999

document

17α-Ethyl-5β-estrane-3α,17β-diol, a biological marker for the abuse of norethandrolone and ethylestrenol in slaughter cattle

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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Participation of beta-adrenergic receptors on macrophages in modulation of lps-induces cytokine release

Izeboud, C.A. (author), Mocking, J.A.J. (author), Monshouwer, M. (author), van Miert, A.S.J.P.A.M. (author), Witkamp, R.F. (author)

article 1999

document

The beta-adrenoceptor agonist clenbuterol is a potent inhibitor of the LPS-inducedproduction of TNF-alpha and IL-6 in vitro and in vivo

Izeboud, C.A. (author), Monshouwer, M. (author), van Miert, A.S.J.P.A.M. (author), Witkamp, R.F. (author)

article 1999

document

Participation of β-adrenergic receptors on macrophages in modulation of LPS-induced cytokine release

Izeboud, C.A. (author), Mocking, J.A.J. (author), Monshouwer, M. (author), van Miert, A.S.J.P.A.M. (author), Witkamp, R.F. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

For several years it is known that β-adrenergic receptor agonists have anti-inflammatory effects. However, little is known about the role of β- adrenergic receptors on macrophages in the modulation of cytokine production by β-agonists during inflammation. In this study, the presence of β- receptors on PMA-differentiated U937 human macrophages,...

article 1999

document

Inhibition of cytochrome P450 by different sulphonamides, non-steroidal anti-inflammatory drugs and macrolides in ruminants: Mechanisms and structure-inhibition relations

Witkamp, R.F. (author), Zweers-Zeilmaker, W.M. (author), Arts, C.J.M. (author), Horbach, G.J. (author), van Miert, A.S.J.P.A.M. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

article 1998

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Characterization of cytochrome P450 isoenzymes in primary cultures of pig hepatocytes

Monshouwer, M. (author), van 't Klooster, G.A.E. (author), Nijmeijer, S.M. (author), Witkamp, R.F. (author), van Miert, A.S.J.P.A.M. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

Despite the fact that pigs are increasingly used in pharmacological and toxicological studies, knowledge on the enzymes which metabolize xenobiotics, in particular cytochrome P450 (CYP) enzymes, in pigs is still very limited. Primary cultures of pig hepatocytes were used to characterize CYP enzymes. The characterization was performed at the...

article 1998

document

Acute-phase response induced down-regulation of hepatic drug metabolism in pigs

Monshouwer, M. (author), Witkamp, R.F. (author), Nijmeijer, S.M. (author), van Miert, A.S.J.P.A.M. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

article 1998

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In vitro complex formation and inhibition of hepatic cytochrome P450 activity by different macrolides and tiamulin in goats and cattle

Zweers-Zeilmaker, W.M. (author), van Miert, A.S.J.P.A.M. (author), Horbach, G.J. (author), Witkamp, R.F. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

In humans, clinically relevant drug–drug interactions occur with some macrolide antibiotics via the formation of stable metabolic intermediate (MI) complexes with enzymes of the cytochrome P4503A (CYP3A) subfamily. The formation of such complexes can result in a decreased biotransformation rate of simultaneously administered drugs. In previous...

article 1998

document

Cloning and stable expression of a bovine cytochrome P450 3A cDNA and its biotransformation activity towards steriods and drugs

Witkamp, R.F. (author), van Raak, M. (author), Natsuhori, M. (author), Ligtenberg, M. (author), Kleij, L. (author), de Groene, E.M. (author), van Miert, A.S.J.P.A.M. (author), Arts, C.J.M. (author), Horbach, G.J. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

article 1998

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The effect of sulfaphenazole and sulfadoxine on tolbutamide disposition in dwarf goats (Caprus hircus aegagrus)

Zweers-Zeilmaker, W.M. (author), Wildschut, S. (author), Witkamp, R.F. (author), van Miert, A.S.J.P.A.M. (author), Centraal Instituut voor Voedingsonderzoek TNO TNO Voeding (author)

article 1997

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Isolation of a bovine full length cytochrome P450 (CYP3A) cDNA sequence and its functional expression in V79 cells

Natsuhori, M. (author), van Raak, M. (author), Ligtenberg, M. (author), Kleij, L. (author), ten Berge, D. (author), Zweers-Zeilmaker, W.M. (author), de Groene, E.M. (author), van Miert, A.S.J.P.A.M. (author), Witkamp, R.F. (author), Horbach, G.J. (author), Centraal Instituut voor Voedingsonderzoek TNO TNO Voeding (author)

article 1997

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Suppression of cytochrome P450- and UDP glucuronosyl transferase-dependent enzyme activities by proinflammatory cytokines and possible role of nitric oxide in primary cultures of pig hepatocytes

Monshouwer, M. (author), Witkamp, R.F. (author), Nijmeijer, S.M. (author), van Amsterdam, J.G. (author), van Miert, A.S.J.P.A.M. (author), TNO Voeding (author)

article 1996

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Cytochrome P-450 complex formation in rat liver by the antibiotic tiamulin

Witkamp, R.F. (author), Nijmeijer, S.M. (author), van Miert, A.S.J.P.A.M. (author), TNO Voeding (author)

article 1996

document

Differential effect of pentoxifylline on lipopolysaccharide-induced downregulation of cytochrome P450

Monshouwer, M. (author), Mclellan, R.A. (author), Delaporte, E. (author), Witkamp, R.F. (author), van Miert, A.S.J.P.A.M. (author), Renton, K.W. (author), TNO Voeding (author)

article 1996

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A lipopolysaccharide-induced acute phase response in the pig is associated with decrease in hepatic cytochrome P450-mediated drug metabolism

Monshouwer, M. (author), Witkamp, R.F. (author), Nijmeijer, S.M. (author), van Leengoed, L.A.M.G. (author), Vernooy, H.C.M. (author), Verheijden, J.H.M. (author), van Miert, A.S.J.P.A.M. (author), TNO Voeding (author)

article 1996