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

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 induceda low frequency of sister chromatid exchanges in human lymphocytecultures in the presence of metabolic activation. Structuralchromosome aberrations were not induced at comparable high concentrationsin human lymphocytes with intact repair system, suggesting thatrepair or induction of point mutations are involved in the DNA-damagingeffect of heterocyclic amines rather than structural chromosomeaberrations. Accordingly it may be concluded that mammaliancells with both intact repair and enzyme systems are more relevantthan bacterial systems for evaluating the carcinogenic potentialof heterocyclic amines.