title: In vitro CYP1A activity in the zebrafish: temporal but low metabolite levels during organogenesis and lack of gender differences in the adult stage.
abstract: The zebrafish (Danio rerio) is increasingly used as a screening model for acute, chronic and developmental toxicity. More specifically, the embryo is currently investigated as a replacement of in vivo developmental toxicity studies, although its biotransformation capacity remains a point of debate. As the cytochrome P450 1 (CYP1) family plays an important role in the biotransformation of several pollutants and drugs, a quantitative in vitro protocol was refined to assess gender- and age-related CYP1A activity in the zebrafish using the ethoxyresorufin-o-deethylase (EROD) assay. Microsomal protein fractions were prepared from livers of adult males and females, ovaries and whole embryo homogenates of different developmental stages. A large biological variation but no gender-related difference in CYP1A activity was observed in adult zebrafish. Embryos showed distinct temporal but low CYP1A activity during organogenesis. These in vitro data raise questions on the bioactivation capacity of zebrafish embryos in developmental toxicity studies.
authors.affiliation: Applied Veterinary Morphology, Department of Veterinary Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Moayad
authors.initials: M
authors.lastname: Saad
authors.affiliation: Applied Veterinary Morphology, Department of Veterinary Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Evy
authors.initials: E
authors.lastname: Verbueken
authors.affiliation: Applied Veterinary Morphology, Department of Veterinary Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Casper
authors.initials: C
authors.lastname: Pype
authors.affiliation: Applied Veterinary Morphology, Department of Veterinary Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Christophe
authors.initials: C
authors.lastname: Casteleyn
authors.affiliation: Applied Veterinary Morphology, Department of Veterinary Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Chris
authors.initials: C
authors.lastname: Van Ginneken
authors.affiliation: Laboratory of Microbiology, Parasitology and Hygiene, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Louis
authors.initials: L
authors.lastname: Maes
authors.affiliation: Laboratory of Microbiology, Parasitology and Hygiene, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Paul
authors.initials: P
authors.lastname: Cos
authors.affiliation: Applied Veterinary Morphology, Department of Veterinary Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium. Electronic address: steven.vancruchten@uantwerpen.be.
authors.forename: Steven
authors.initials: S
authors.lastname: Van Cruchten
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D001711:Biotransformation / Q000502:physiology; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000201:enzymology*; D005260:Female; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology; D038081:Organogenesis / Q000502:physiology*; D012727:Sex Characteristics; D018675:Toxicity Tests / Q000592:standards; D015027:Zebrafish / Q000196:embryology / Q000378:metabolism*
chemical_list: D019363:Cytochrome P-450 CYP1A1
keywords: CYP1A; EROD; Embryo; Gender; Metabolism; Microsomes; Ontogeny; Zebrafish