INDUCTION OF SISTER CHROMATID EXCHANGES IN CHINESE-HAMSTER CELLS BY THE REDUCING AGENTS BISULFITE AND ASCORBIC-ACID

Sister chromatid exchanges (SCE) were induced in Chinese hamster cells by a 2-3 h exposure to ascorbic acid (sodium ascorbate) or bisulfite in the concentration range 10-4-10-2 M. This activity of these 2 chemicals was intensified when cell cultures were exposed to each agent for longer time periods (24 h). The divalent metal cation, Cu2+, was effective in potentiating the ability of ascorbic acid to induce SCE and toxicity, suggesting that the autooxidation of ascorbic acid was involved in this action. The ability of sodium bisulfite to induce SCE was not affected by variation in the concentration of 5''-bromodeoxyuridine [BrdU] used as a labeling compound. Bisulfite by itself was apparently responsible for the elevated SCE levels rather than a synergistic reaction between bisulfite and BrdU. [Sodium ascorbate and sodium bisulfite are both ubiquitous chemicals in man''s environment.].