Metabolism of benzo[a]pyrene by cultured human hepatocytes from multiple donors

Abstract

Primary hepatocyte cultures from six human donors were established and their abilities to metabolize the polycyclic aromatic hydrocarbon carcinogen benzo[a]pyrene (B[a]P) were examined. Cells from each donor were plated at similar densities (1 X 10(7) cells/100 mm dish). All cultures metabolized B[a]P to a significant extent (24-35 nmol in 24 h) and h.p.l.c. profiles of the organic solvent-soluble and glucuronidated B[a]P metabolites were obtained for all donors. The predominant extracellular organic solvent-soluble B[a]P metabolites were the 9,10- and 7,8-dihydrodiols, 9-hydroxy-B[a]P, and a mixture of tetrols, but the general ratios of these metabolites varied widely among the cells from different donors. In contrast, profiles were highly reproducible in cells from the same donor treated with B[a]P at either 8 or 24 h after initial plating. There was less variability in the amounts of specific B[a]P metabolites conjugated to glucuronic acid by cells from various donors. This variability could not be correlated with cell viability or overall levels of B[a]P metabolism. In addition, B[a]P metabolism by fresh and cryopreserved hepatocytes from the same donor was compared. While there was only a small reduction in the level of total B[a]P metabolism after cell freezing, there was a 3- to 5-fold increase in production of B[a]P-7,8-dihydrodiol, found both in the extracellular medium and as glucuronic acid conjugates, by the cryopreserved cells tested.

Time-Dependent Inhibition and Estimation of CYP3A Clinical Pharmacokinetic Drug-Drug Interactions Using Plated Human Cell Systems

“…The longer duration of the testing was due to the limited availability of cells from human donors with acceptable demographics and CYP3A activity. During the course of this study, we observed substantial donor-to-donor variability in CYP3A activity (data not shown), consistent with previous literature (Moore and Gould, 1984). In addition, the cost of purchasing the plated hepatocytes is substantially higher than using human liver microsomes.…”

Comparison of the Sensitivity of Human and Rat Hepatocytes to the Genotoxic Effects of Metronidazole

“…as due to the presence of neoplastic lesions or other pathological changes in the liver of the five donors. However, primary cultures of human hepatocytes have been shown to display in the amount of DNA damage and repair induced by genotoxic agents a donor to donor variation more marked than that observed in cultures derived from rats (Harris et al 1987;Martelli et al 1988;Butterworth et al 1989), and great interindividual differences have been reported for the metabolism of some carcinogens (Moore & Gould 1984;Butler er al. 1989).…”

Carcinogenic response of hamster buccal pouch epithelium to 4 polycyclic aromatic hydrocarbons

“…Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants resulting from eombustion and pyrolysis of organie matter (1)(2)(3). Cells and tissues of various species including man, metabolize a spectrum of PAHs to reactive genotoxic molecules which are potent mutagens and carcinogens (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17). PAHs are present in tobacco smoke (18)(19)(20)(21)(22) and may contribute to the development of tobacco related cancers of oral mucosa and contiguous structures (23)(24)(25).…”