ANEUGENIC EFFECT OF SODIUM ARSENITE ON HUMAN-LYMPHOCYTES IN-VITRO - AN INDIVIDUAL SUSCEPTIBILITY EFFECT DETECTED

Arsenic is a well known carcinogenic environmental pollutant although its mechanism of action remains unknown. Since alterations in chromoso me segregation have been observed in individuals exposed to high conce ntrations of arsenic in the drinking water, the aneuploidogenic potent ial of arsenic was evaluated in vitro. Whole blood cultures were incub ated for 72 h and treated with various concentrations of sodium arseni te for the last 24 h. Cells were harvested and samples were processed specially for aneuploidy evaluation. The number of chromosomes in 200 metaphases of first and second division cells was scored. A dose-relat ed effect was observed: the highest concentration (10(-2) mu M) induce s 28.33% and 22.4% hyperploid cells in first and second division respe ctively and 29% tetraploid cells. The colchicine-like effect of arseni c was also evaluated. Mitotic arrest was evaluated in cultures treated for the last 2 h. Sodium arsenite can produce 40.24% and 12.93% of th e colcemid effect (mitotic arrestant effect at 10(-2) mu M and 10(-10) mu M respectively). A different individual susceptibility effect was observed in both parameters and confirmed with the chromosome aberrati ons levels induced by arsenic in the same donors. Data indicate that s odium arsenite has an aneuploidogenic and a mitotic arrestant effect.