OXIDATIVE STRESS-INDUCED CADMIUM RESISTANCE IN CHINESE-HAMSTER V79 CELLS

Pretreatment with low dose of H2O2 failed to induce resistance to furt her treatment with toxic doses of H2O2 in a radioresistant cell strain M5 in contrast to parental V79 cells. In parental cells, reduced glut athione (GSH) level increased up to (2.02 +/- 0.04) mu M per 10(6) cel ls from the untreated control value of (1.59 +/- 0.08) mu M per 10(6) cells, within 30 minutes after treatment. This increase was found to b e 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 whe re the GSH was reduced to minimum, the pretreated cells exhibited resi stance to CdCl2 indicating that metallothioneines may play an importan t role in protecting cells in such condition. (C) 1996 Academic Press, Inc.