DIFFERENTIAL-EFFECTS OF PRETREATMENT AND POSTTREATMENT OF SODIUM ARSENITE ON THE GENOTOXICITY OF METHYL METHANESULFONATE IN CHINESE-HAMSTER OVARY CELLS

  • 1 April 1986
    • journal article
    • research article
    • Vol. 46  (4) , 1854-1857
Abstract
Pretreatment of sodium arsenite reduces hypoxanthine-guanine phosphoribosyltransferase mutagenicity and overcomes the inhibition of mitosis and cell proliferation but has no apparent effect on the cytotoxicity and clastogenicity in methyl methanesulfonate (MMS)-treated Chinese hamster ovary cells. Posttreatment of sodium arsenite drastically increases the cytotoxicity, clastogenicity, hypoxanthine-guanine phosphoribosyltransferase mutagenicity, and inhibition of mitosis and cell proliferation induced by MMS. Sodium arsensite either pre- or posttreatment has no apparent effect on the MMS-induced sister chromatid exchanges. The present results indicate that pretreatment of sodium arsenite not only does no harm but may even benefit the MMS-treated cells. On the contrary, posttreatment of sodium arsenite is cogenotoxic.