Responses of the L5178Y mouse lymphoma cell forward mutation assay. V: 27 coded chemicals

Twenty-seven chemicals were tested for their mutagenic potential in the L5178Y tk+/tk− mouse lymphoma cell forward mutation assay using procedures based upon those described by McGregor et al. (McGregor DB, Martin R, Cattanach P, Edwards I, McBride D, Caspary WJ (1987): Environ Mol Mutagen 9:143–160). Cultures were exposed to the chemicals for 4 hr, then cultured for 2 days before plating in soft agar with or without trifluorothymidine (TFT), 3 μg/ml. The chemicals were tested at least twice. Statistically significant responses were obtained with acid orange 10, aniline, benzaldehyde, o-chloroaniline, chlorodibromomethane, cytembena, 1,2-dibromo-4-(1,2-dibromomethyl) cyclohexane, dieldrin, lithocholic acid, oxytetracycline, phenazopyridine HCl, 1-phenyl-3-methyl-5-pyrazolone, sodium diethyldithiocarbamate, solvent yellow 14, tetraethylthiuram disulfide (disulfiram), 2,4-toluene diisocyanate, and 2,6-toluene diisocyanate. Apart from phenazopyridine HCl, acid orange 10, and solvent yellow 14, rat liver S9 mix was not a requirement for the mutagenic activity of these compounds. Chemicals not identified as mutagens were N-4-acetylaminofluorene, chlorpheniramine maleate, chlorpropamide, 1,4-dioxane, endrin, ethylene glycol, iron dextran, methapyrilene, sodium(2-ethylhexyl)alcohol sulfate, and 2,3,7,8-tetra-chlorodibenzo-p-dioxin.