title: In vitro kinetics of amiodarone and its major metabolite in two human liver cell models after acute and repeated treatments.
abstract: The limited value of in vitro toxicity data for the in vivo extrapolation has been often attributed to the lack of kinetic data. Here the in vitro kinetics of amiodarone (AMI) and its mono-N-desethyl (MDEA) metabolite was determined and modelled in primary human hepatocytes (PHH) and HepaRG cells, after single and repeated administration of clinically relevant concentrations. AMI bioavailability was influenced by adsorption to the plastic and the presence of protein in the medium (e.g. 10% serum protein reduced the uptake by half in HepaRG cells). The cell uptake was quick (within 3h), AMI metabolism was efficient and a dynamic equilibrium was reached in about a week after multiple dosing. In HepaRG cells the metabolic clearance was higher than in PHH and increased over time, as well as CYP3A4. The interindividual variability in MDEA production in PHHs was not proportional to the differences in CYP3A4 activities, suggesting the involvement of other CYPs and/or AMI-related CYP inhibition. After repeated treatment AMI showed a slight potential for bioaccumulation, whereas much higher intracellular MDEA levels accumulated over time, especially in the HepaRG cells, associated with occurrence of phospholipidosis. The knowledge of in vitro biokinetics is important to transform an actual in vitro concentration-effect into an in vivo dose-effect relationship by using appropriate modelling, thus improving the in vitro-to-in vivo extrapolation.
authors.affiliation: Mechanism of Toxicity Unit, Environment and Primary Prevention Department, Istituto Superiore di Sanità, Rome, Italy; Università Sapienza, Dipartimento di Fisiologia "V. Erspamer", Rome, Italy.
authors.forename: Giuliana
authors.initials: G
authors.lastname: Pomponio
authors.affiliation: Institut National de la Santé et de la Recherche Médicale (Inserm), UMR991, Université de Rennes 1, Rennes, France.
authors.forename: Camille C
authors.initials: CC
authors.lastname: Savary
authors.affiliation: KaLy-Cell, 20A Rue du Général Leclerc, Plobsheim, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Parmentier
authors.affiliation: Institut National de L'Environnement Industriel et des Risques, DRC/VIVA/METO, Verneuil en Halatte, France.
authors.forename: Frederic
authors.initials: F
authors.lastname: Bois
authors.affiliation: Institut National de la Santé et de la Recherche Médicale (Inserm), UMR991, Université de Rennes 1, Rennes, France.
authors.forename: André
authors.initials: A
authors.lastname: Guillouzo
authors.affiliation: Università Sapienza, Dipartimento di Fisiologia "V. Erspamer", Rome, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Romanelli
authors.affiliation: KaLy-Cell, 20A Rue du Général Leclerc, Plobsheim, France; Universite de Franche-Comté, Besançon, France.
authors.forename: Lysiane
authors.initials: L
authors.lastname: Richert
authors.affiliation: Mechanism of Toxicity Unit, Environment and Primary Prevention Department, Istituto Superiore di Sanità, Rome, Italy. Electronic address: emma.diconsiglio@iss.it.
authors.forename: Emma
authors.initials: E
authors.lastname: Di Consiglio
authors.affiliation: Mechanism of Toxicity Unit, Environment and Primary Prevention Department, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Testai
mesh_terms: D000638:Amiodarone / Q000378:metabolism / Q000493:pharmacokinetics*; D002460:Cell Line; D051544:Cytochrome P-450 CYP3A / Q000235:genetics / Q000378:metabolism; D004334:Drug Administration Schedule; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D006801:Humans
chemical_list: C510164:CYP3A5 protein, human; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; D000638:Amiodarone
keywords: Amiodarone; Biokinetics; HepaRG cells; In vitro biokinetic model; Primary human hepatocytes; Repeated exposure