title: Hepatocytes as in vitro test system to investigate metabolite patterns of pesticides in farmed rainbow trout and common carp: Comparison between in vivo and in vitro and across species.
abstract: In vitro tools using isolated primary fish hepatocytes have been proposed as a useful model to study the hepatic metabolism of xenobiotics in fish. In order to evaluate the potential of in vitro fish hepatocyte assays to provide information on in vivo metabolite patterns of pesticides in farmed fish, the present study addressed the following questions: Are in vitro and in vivo metabolite patterns comparable? Are species specific differences of metabolite patterns in vivo reflected in vitro? Are metabolite patterns obtained from cryopreserved hepatocytes comparable to those from freshly isolated cells? Rainbow trout and common carp were dosed orally with feed containing the pesticide methoxychlor (MXC) for 14days. In parallel, in vitro incubations using suspensions of freshly isolated or cryopreserved primary hepatocytes obtained from both species were performed. In vivo and in vitro samples were analyzed by thin-layer chromatography with authentic standards supported by HPLC-MS. Comparable metabolite patterns from a qualitative perspective were observed in liver in vivo and in hepatocyte suspensions in vitro. Species specific differences of MXC metabolite patterns observed between rainbow trout and common carp in vivo were well reflected by experiments with hepatocytes in vitro. Finally, cryopreserved hepatocytes produced comparable metabolite patterns to freshly isolated cells. The results of this study indicate that the in vitro hepatocyte assay could be used to identify metabolite patterns of pesticides in farmed fish and could thus serve as a valuable tool to support in vivo studies as required for pesticides approval according to the EU regulation 1107.
authors.affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology, Auf dem Aberg 1, 57392 Schmallenberg, Germany; Centre for Fish and Wildlife Health, University of Bern, Switzerland. Electronic address: ina.bischof@ime.fraunhofer.de.
authors.forename: Ina
authors.initials: I
authors.lastname: Bischof
authors.affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology, Auf dem Aberg 1, 57392 Schmallenberg, Germany.
authors.forename: Jessica
authors.initials: J
authors.lastname: Köster
authors.affiliation: Centre for Fish and Wildlife Health, University of Bern, Switzerland.
authors.forename: Helmut
authors.initials: H
authors.lastname: Segner
authors.affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology, Auf dem Aberg 1, 57392 Schmallenberg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Schlechtriem
mesh_terms: D000818:Animals; D001711:Biotransformation; D002347:Carps / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D015925:Cryopreservation; D005398:Fisheries; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D013058:Mass Spectrometry; D055432:Metabolomics / Q000379:methods; D008731:Methoxychlor / Q000378:metabolism* / Q000633:toxicity; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D010575:Pesticides / Q000378:metabolism* / Q000633:toxicity; D013045:Species Specificity; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000633:toxicity
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical; D008731:Methoxychlor
keywords: Common carp; Fish; Hepatocytes; In vitro; Metabolism; Metabolite pattern; Methoxychlor; Pesticide regulation; Rainbow trout; Species differences