ANEUPLOIDY INDUCTION BY BENZO[A]PYRENE AND POLYPLOIDY INDUCTION BY 7,12-DIMETHYLBENZ[A]ANTHRACENE IN CHINESE-HAMSTER CELL-LINES V79-MZ AND V79

We found that different ploidy effects were induced in four Chinese ha mster-derived cell lines (V79-MZ, V79, CHL and CHO-K1) treated through two cell cycles with polycyclic aromatic hydrocarbons in the absence of a metabolic activation system, 5-Bromodeoxyuridine was used to inve stigate cell cycle delay and sister chromatid exchanges (SCE) induced by the chemicals, Benzo[a]pyrene (BP) induced aneuploidy at 2.5-10 mu g/ml in V79-MZ cells. 7,12-Dimethylbenz[a]anthracene (DMBA) induced po lyploidy at 3.125-6.25 and 6.25-12.5 mu g/ml in V79-MZ and V79 cells r espectively, Higher concentrations caused cell cycle delay and, theref ore, did not affect ploidy, BP and DMBA did not induce a significant i ncrease in SCE frequency at the above doses, 3-Methylcholanthrene test ed up to its solubility limit (10 mu g/ml) did not induce numerical ab errations in any cell line, The clastogen mitomycin C, tested up to 0. 01 mu g/ml, did not produce numerical aberrations but did significantl y increase SCE frequency in all cell lines, The spindle poison colchic ine, tested up to 0.1 mu g/ml, induced ploidy changes in the four cell lines that showed different sensitivities, Four cell lines showed no arylhydrocarbon hydroxylase activity, and V79-MZ, but not the other ce lls lines, showed high glutathione S-transferase activity, Aneuploidy induction by BP and polyploidy induction by DMBA in the absence of S9 mix in vitro have not been described before, and the finding might be due to the effect on tubulin, Due to their specificity and high sensit ivity, the V79-MZ and V79 cell lines might be good systems for detecti ng aneuploidogens.