Genotoxic action of cadmium and mercury in cell cultures and modulation of radiation effects†

Abstract

The effects of cadmium and mercury chlorides, alone or in combination with X‐rays, on the genome of V79‐M3–1 and muscle cells was studied using the alkaline unwinding assay to quantify DNA strand breaks. The induction of primary damage, its repair or enhancement during posttreatment incubation at 37°C were investigated. Prolonged treatment of V79 and muscle cells with cadmium (II) or mercury (II) chloride leads to an accumulation of DNA strand breaks. Strong effects were seen at micromolar metal concentrations for mercury. Given in combination with ionizing radiation, cadmium seems to modulate the primary damage caused by X‐rays. Depending on the concentration and time between treatment, enhancing or slight inhibitory effects on the yield of DNA strand breaks are found. Higher cadmium concentrations inhibit repair of DNA strand breaks caused by ionizing radiation.