Species difference between rats and mice in activities of enzymes activating aromatic amines: effect of dietary 3-methoxy-4-aminoazobenzene.

Male Donryu rats and B6C3F1 mice were treated with dietary 3-methoxy-4-aminoazobenzene (3-MeO-AAB) (0.06% or 0.09%), and subcellular fractions of the liver were examined for ability to mutagenically activate 3-MeO-AAB and 2 amino acid pyrolysate components using Salmonella typhimurium TA 98 as a tester strain. The treatment resulted in striking induction of enzyme(s) for the mutagenic activation of these aromatic amines in rats, but the effect was smaller in mice. The enzyme(s) involved in the reaction was characterized as an isotype of microsomal cytochrome P-448.