Individual and combined cytotoxic effects of cadmium, copper, and nickel on brown cells of Mercenaria mercenaria

Abstract An assay based on the lysosomal incorporation of neutral red dye by brown cells of Mercenaria mercenaria (Bivalvia) was used to measure the cytotoxicity of Cd 2+ , Cu 2+ , and Ni 2+ singly and in combination. Cytotoxicity was a linear function of Cd 2+ concentration 0.1–1.5 m M and Cu 2+ concentration between 10 and 100 μ M . Nickel was not cytotoxic at concentrations as high as 10 m M . The presence of Cu 2+ lessened the cytotoxic effect of Cd 2+ . Ni 2+ did not affect cytotoxicity in combination with either Cu 2+ or Cd 2+ . Ni 2+ inflated estimates of cell survival by the neutral red assay in this study. Cells exposed to Ni 2+ yielded measured quantities of neutral red dye in excess of those measured in cells from control treatments.