Developmental changes in hepatic activation of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline in rabbit

MeIQx, a potent bacterial mutagen formed when meat is cooked, requires metabolic activation to exert its genotoxicity, a reaction catalysed primarily by CYP1A2 in adult mammals. Little is known about mammalian developmental changes in the mutagneic activation of compounds such as MeIQx. In rabbits we have shown previously that expression of CYP1A2 increases with age and is inducible by 3-methylcholanthrene (MC) from as early as 4 days pre-parturition. We have therefore investigated the effect of age on rabbit liver activation of MeIQx (assessed in an Ames test using Salmonella typhimurium TA98) before and after treatment of the animals with MC. MeIQx activation could not be detected using hepatic microsomal fractions from rabbits of