Enhancement of the activity of bleomycin by cysteamine in a micronucleus assay in G0 human lymphocytes

Abstract

The aminothiol cysteamine enhances the induction of micronuclei by bleomycin in G0 human lymphocytes. The potentiation of bleomycin (12.5, 25, 50, or 100 micrograms/ml) increased with cysteamine concentration from 5 to 20 mM in a 2-h treatment before culturing the cells for the cytokinesis-block assay. The maximum clastogenic activity of bleomycin in the presence of cysteamine was more than 10-fold greater than that of the same dosage of bleomycin alone. Both the thiol and amine functions of aminothiols seem to contribute to the potentiation of bleomycin.