EFFECTS OF L-ASCORBIC-ACID ON THE MUTAGENICITY OF ETHYL METHANESULFONATE IN CULTURED-MAMMALIAN-CELLS

The effects Of L-ascorbic acid (AsA) on the mutations induced by ethyl methanesulfonate (EMS) were examined by means of the 6-thioguanine (6TG)-resistant mutation assay and chromosome aberration assay in cultured Chinese hamster V79 cells. When cells were treated with EMS at various concentrations in the presence of 100-mu-g/ml AsA, EMS-induced 6TG-resistant mutations were reduced about one third or one fourth. EMS-induced chromosome aberrations were also reduced by AsA. These reductions in the mutagenicity of EMS were also found when cells were treated with mixtures of AsA and EMS which had previously been incubated at 37.0-degrees-C for 2 h. In pre- and post-treatments with AsA, however, the frequencies of EMS-induced mutations were not reduced, but rather increased markedly.