Bleomycin-induced chromosome aberrations in the lymphocytes of young and elderly patients.

Phytohaemagglutinin-stimulated lymphocytes from 20 young (16-28 years) and 20 old (70-88 years) healthy subjects were examined for chromosome aberrations before and after exposure to bleomycin in the G2 phase of the cell cycle. No differences were found in unexposed cultures between young and old donors. After treatment with bleomycin, the rate of chromosome aberrations was significantly higher in the elderly persons (p less than 0.05). As the results suggest, different interaction between the mutagen and DNA may be caused by the decreased capacity of the excision repair system in the elderly individuals cells.