Absence of arsenite mutagenicity in E coli and chinese hamster cells

Abstract

Because exposure to compounds of arsenic has been implicated as a cause of cancer, an investigation of the mutagenicity of sodium aresenite in E coli and in Chinese hamster cells was performed. In the E coli system, Trp revertants were not induced by arsenite in a variety of experimental protocols including spot tests, treat and plate protocols, and fluctuation tests. The mutator effect of a tif‐1 strain was partially blocked by arsenite. Arsenite did not cause the induction of λ prophage. In Chinese hamster cells, arsenite did not induce ouabain‐resistant mutants or thioguanine‐resistant mutants. We conclude that arsenite is not mutagenic to E coli or to Chinese hamster cells. When added to the plating medium, arsenite can act as an anti‐mutagen by inhibition of induction of the error‐prone SOS repair system in E coli.