THE METABOLISM OF BENZO[a]PYRENE IN CELL CULTURES AND HOMOGENATES FROM DIFFERENT HUMAN FETAL TISSUES

Benzo(a)pyrene is efficiently metabolised by cells derived from human fetal tissues into known (dihydrodiols, phenols, quinones) and unknown metabolites. Benzo(a)pyrene metabolism in cell cultures does not necessarily represent the activity of aryl hydrocarbon hydroxylase in the original tissue in vitro . The intraindividual variability of benzo(a)pyrene metabolism is only about 15 per cent in liver cell cultures and very large, several fold, in different fibroblast cultures. At least part of the intraindividual variability can be overcome by subculturing fetal fibroblasts. Interindividual variability is 5- to 10-fold, a figure also obtained by others in different human cell and tissue culture systems. When compared to some established cell lines, for instance BS-C-1 or BHK-21, human fetal cell cultures metabolise benzo(a)-pyrene to a comparable extent. Human fetal cells in culture seem to be promising models for studying the significance of carcinogen metabolism in terms of toxicity, mutagenicity and carcinogenicity.