32P-postlabeling analysis of DNA adducts in rat livers after treatment with genotoxic and non-genotoxic 4-aminoazobenzene derivatives.
Formation of hepatic DNA adducts was studied in rats following intraperitoneal administration of a hepatocarcinogen, 3-methoxy-4-aminoazobenzene (3-MeO-AAB) and a non-hepatocarcinogen, 2-methoxy-4-aminoazobenzene (2-MeO-AAB). The 32P-post-labeling assay revealed 3-MeO-AAB to give more than 20-fold higher amounts of DNA adducts than did 2-MeO-AAB. Furthermore, five adducts, one of which accounted for over 70% of the total modified bases, were found in DNA from 3-MeO-AAB-treated rats, whereas only one adduct was apparent in 2-MeO-AAB-treated DNA. Our data thus suggested that the difference in hepatocarcinogenic activity between 3-MeO-AAB and 2-MeO-AAB might be, at least in part, dependent on quantitative and qualitative differences in their azo dye-DNA adduct formation in the rat liver.
Kojima
M
M
Laboratory of Biochemistry, Aichi Cancer Center Research Institute, Kanokoden, Nagoya, Japan.
Degawa
M
M
Hashimoto
Y
Y
Tada
M
M
D000818:Animals; D002273:Carcinogens / Q000494:pharmacology*; D004247:DNA / Q000187:drug effects*; D004249:DNA Damage; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010761:Phosphorus Radioisotopes; D051381:Rats; D011916:Rats, Inbred F344; D010128:p-Aminoazobenzene / Q000031:analogs & derivatives* / Q000494:pharmacology
D002273:Carcinogens; D010761:Phosphorus Radioisotopes; C053767:2-methoxy-4-aminoazobenzene; D010128:p-Aminoazobenzene; C044436:3-methoxy-4-aminoazobenzene; D004247:DNA