Sulfur amino acid deprivation in cadmium chloride toxicity in hepatoma cells

The aim of this study was to investigate the effect of individual sulfur amino acid deprivation in cadmium chloride toxicity. HTC cells were deprived of cystine and/or methionine for 12 h and then exposed to CdCl2 for 12 h. HepG2 cells were deprived of cystine for 3 and 5 h and exposed to CdCl2 for 3 h. In addition HepG2 cells were deprived of methionine for 12 h and then exposed to CdCl2 for 5 and 12 h. Our results indicate that only cystine depletion increased cadmium toxicity in HTC cells but not in HepG2 cells as indicated by the neutral red assay. This effect was due to glutathione depletion as indicated by measurement of intracellular glutathione in HTC cells following deprivation of cystine. Methionine depletion had only a slight effect on the viability of HepG2 cells.