Effect of trivalent and pentavalent arsenic in causing chromosome alterations in cultured Chinese hamster ovary (CHO) cells.

Sodium salts of trivalent and pentavalent arsenic were tested for their effect in inducing chromosome aberrations and sister-chromatid exchange (SCE) in cultured Chinese hamster ovary (CHO) cells. It was discovered that arsenite (As 3) produced excessive endoreduplication of the chromosomes at higher levels. No endoreduplication was observed with arsenate (As 5) treatment. These agents also elevated the frequencies of SCE, but less so compared to aberrations. The results obtained indicate that arsenic may be carcinogenic in animal system.