Mutagenic effect of thallium and mercury salts on rodent cells with different repair activities.

The mutagenic activity of thallium carbonate and mercury chloride was estimated by the HAP chromatography and virus reactivation methods in cultures of embryo cells of mice (CBA and C57Bl/6 strains) and rats and by the dominant mutation frequency in rats. Thallium carbonate induced single-stranded DNA breaks. The induction of DNA breaks correlated with the rate of virus reactivation and the mutability of vaccinia virus in the cell cultures studied. DNA breaks in experiments with mercury chloride occurred at much lower concentrations as compared with these of thallium carbonate. The rate of vaccinia virus reactivation in cells treated with mercury chloride was reduced, whereas the level of virus mutagenesis did not differ from the control. In the dominant lethal test the mutagenic activity of thallium carbonate was higher than the mutagenic activity of mercury chloride.