Effect of heterocyclic amines and beef extract on chromosome aberrations and sister chromatid exchanges in cultured...

Two of the major bacterial mutagens formed in heated meat products, 2-amino-3-methylimidazo[4,5-f]quinoline and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline or the basic fraction of beef extract induced a low frequency of sister chromatid exchanges in human lymphocyte cultures in the presence of metabolic activation. Structural chromosome aberrations were not induced at comparable high concentrations in human lymphocytes with intact repair system, suggesting that repair or induction of point mutations are involved in the DNA-damaging effect of heterocyclic amines rather than structural chromosome aberrations. Accordingly it may be concluded that mammalian cells with both intact repair and enzyme systems are more relevant than bacterial systems for evaluating the carcinogenic potential of heterocyclic amines.