Comparative studies of chromosomal aberration induced by trivalent and pentavalent arsenic.

The comparative cytogenetic effects on the synthesis of DNA, RNA and protein in cultured mammalian cells of trivalent and pentavalent arsenic were investigated. The chromosome-breaking activity in cultured leukocytes was significantly higher for the compounds with trivalent (NaAsO2, AsCl3 and As2O3) than with pentavalent arsenic (Na2HAsO4, H3AsO4 and As2O5). The activity in cultured human skin fibroblasts was similar to that in leukocyte cultures. The colony-forming capacity after exposure to arsenicals indicated that trivalent was more toxic than pentavalent arsenic. In the response of DNA, RNA and protein synthesis, both trivalent and pentavalent arsenic inhibited DNA and protein synthesis in leukocytes.