Mutagenicity of metal cations in cultured cells from Chinese hamster

The mutations at the hypoxanthine-guanine phosphoribosyl transferase (HGPRTase) locus in Chinese hamster V79 cells induced by metal cations were examined by the development of resistance to 8-azaguanine (8AG). The spontaneous frequency of 8AG resistance was 5.8 per 10(6) cells, and the frequency was enhanced to 2-6 times that of the control by treatment of cells with the chlorides of beryllium and manganese. About 75% of 8AG-resistant colonies were sensitive to amethopterin, and 86% of the resistant colonies showed less than 3% of the HGPRTase activity of the wild-type cells. The mutant frequency in cultures treated with cobalt and nickel chlorides were slightly increased, and mutation induction was only detectable at very low rates of cell survival.