ATLA::Alternatives to Laboratory Animals

Volume 27, Number 4

The use of long-term hepatocyte cultures for detecting induction of drug metabolising enzymes: the current status.
ECVAM Hepatocytes and Metabolically Competent Systems Task Force Report 1

ATLA 27, 579-638, July/August 1999

Sandra Coecke,1 Vera Rogiers,2 Martin Bayliss,3 Jos&eaucte; Castll,4, Johannes Doehmer,5 Gérard Fabre,6 Jeffrey Fry,7 Armin Kern8 and Carl Wetmoreland3

1ECVAM, Institute for Health & Consumer Protection, European Commission Joint Research Centre, 21020 Ispra (VA), Italy; 2Department of Toxicology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; 3GlaxoWellcome Research and Development, Park Road, Ware, Hertfordshire SG12 ODP, UK; 4Unidad de Hepatologia Experimental, Hospital Universitario La Fe, Avda de Campanar 21, 46009 Valencia, Spain; 5Institut für Toxikologie und Umwelthygiene, Technische Universität Munchen, Lazarettstrasse 62, 80636 Munich, Germany; 6Preclinical Metabolism and Pharmacokinetics, Sanofi Recherche, Rue du Professeur Blayac 371, 34184 Montpellier Cedex 04, France; 7School of Biomedical Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham NG7 2UH, UK; 8Drug Metabolism and Isotope Chemistry, Bayer, Aprather Weg 18a, 42096 Wuppertal, Germany

SUMMARY

In this report, metabolically competent in vitro systems have been reviewed in the context of drug metabolising enzyme induction. Based on the experience of the scientists involved, a thorough survey of the literature on metabolically competent long-term culture models was performed. Following this, a prevalidation proposal for the use of the collagen gel sandwich hepatocyte culture system for drug metabolising enzyme induction was designed focusing on the induction of the cytochrome P450 enzymes as the principal enzymes of interest. The ultimate goal of this prevalidation proposal is to provide industry and academia with a metabolically competent in uitro alternative for long-term studies. In an initial phase, the prevalidation study will be limited to the investigation of induction. However, proposals for other long-term applications of these systems should be forwarded to the European Centre for the Validation of Alternative Methods for consideration. The prevalidation proposal deals with several issues, including: a) species, b) practical prevalidation methodology, c) enzyme inducers and d) advantages of working with independent expert laboratories. Since it is preferable to include other alternative tests for drug metabolising enzyme induction when such tests arise it is recommended that they meet the same level of development as for the collagen gel sandwich long-term hepatocyte system. Those tests which do so should begin the prevalidation and validation process.

Keywords: long-term culture, hepatocytes, drug metaoolism, enzyme regulation, induction, cytochrome P450, CYP, collagen gel culture, organotypic culture, co-culture, spheroids