Factors influencing cadmium uptake and cytotoxicity in cultured cells

Cultured Chinese hamster B14F28 and HeLa cells in early lag and stationary phases accumulated less cadmium than cells in logarithmic growth. Pretreatment of the cell cultures with a non-toxic concentration of cadmium lead to adaptation of the response to subsequent high concentrations. The pretreated cells did not differ from controls in their uptake of cadmium. HeLa cell cultures accumulated more cadmium than B14F28 cultures and differed in their sensitivity to cadmium. The cytotoxicity of cadmium in the two cell lines did not correlate with uptake of cadmium. Cells accumulated more cadmium and exhibited enhanced toxicity with increasing pH of the medium. Serum and serum albumin reduced the uptake of cadmium and the cytotoxicity. Increasing concentrations of calcium ions depressed the uptake of cadmium, while magnesium and phosphate ions exerted no effect.