Kojima M, Degawa M, Hashimoto Y, Tada M
Laboratory of Biochemistry, Aichi Cancer Center Research Institute, Kanokoden, Nagoya, Japan.
Cancer Lett. 1991 Jul 4;58(3):199-204. doi: 10.1016/0304-3835(91)90101-m.
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.
在大鼠腹腔注射一种肝癌致癌物3-甲氧基-4-氨基偶氮苯(3-MeO-AAB)和一种非肝癌致癌物2-甲氧基-4-氨基偶氮苯(2-MeO-AAB)后,研究了肝脏DNA加合物的形成。32P后标记分析显示,3-MeO-AAB产生的DNA加合物量比2-MeO-AAB高出20多倍。此外,在3-MeO-AAB处理的大鼠的DNA中发现了五种加合物,其中一种占总修饰碱基的70%以上,而在2-MeO-AAB处理的DNA中仅有一种加合物明显。因此,我们的数据表明,3-MeO-AAB和2-MeO-AAB之间致癌活性的差异可能至少部分取决于它们在大鼠肝脏中偶氮染料-DNA加合物形成的数量和质量差异。