Oxidative stress-induced cadmium resistance in Chinese hamster V79 cells.

Pretreatment with low dose of H2O2 failed to induce resistance to further treatment with toxic doses of H2O2 in a radioresistant cell strain M5 in contrast to parental V79 cells. In parental cells, reduced glutathione (GSH) level increased up to (2.02 +/- 0.04) microM per 10(6) cells from the untreated control value of (1.59 +/- 0.08) microM per 10(6) cells, within 30 minutes after treatment. This increase was found to be significant (p < 0.05). There after, level of GSH decreased to (1.01 +/- 0.02) uM per 10(6) cells (p < 0.02) within 20 h. This value again increased to untreated control value after 40 h. In the condition where the GSH was reduced to minimum, the pretreated cells exhibited resistance to CdCl2 indicating that metallothioneines may play an important role in protecting cells in such condition.