The anticlastogenic effect of various combinations of cysteamine, AET, HCT, and amino acids on chromosome damage by trenimon and bleomycin in human lymphocytes in vitro.

The protective activity of the combined application of anticlastogens against the chromosome-damaging action of Trenimon and bleomycin was studied by analyzing more than 32000 metaphases from cultures of human peripheral lymphocytes. Screening tests with the combinations cysteine/cysteamine/AET, cysteine/methionine/asparagine, cysteine/serine/HCT, and AET/HCT, with Trenimon as clastogen, in no case revealed a hyperadditive (synergistic) effect. From the results of detailed analyses of the action of the combination AET/HCT it was concluded that the (nonsynergistic) anticlastogenic effects observed were induced due to intracellular biologic mechanism, and not due to a reaction in the culture fluid between clastogens and anticlastogens. Although the observations gained with Trenimon or bleomycin differed in some respects, the anticlastogens apparently act via a mechanism at least common to AET and HCT, i.e., they manifest their effect in lymphocyte cultures by a limited interaction with the process of aberration formation, rather than by influencing repair processes, which are blocked by caffeine.