Saito K, Nakagawa S, Yoshitake A, Miyamoto J, Hirose M, Ito N
Biochemistry and Toxicology Laboratory, Sumitomo Chemical Co., Ltd., Osaka, Japan.
Cancer Lett. 1989 Dec;48(3):189-95. doi: 10.1016/0304-3835(89)90117-1.
Formation of DNA-adducts by 3-BHA or its metabolites, i.e., tert-butyl-1,4-benzoquinone (TBQ) and 5-methoxy-3-tert-butyl-1,2-benzoquinone (3-TBOQ), as well as DNA-adduct formation by 4-nitroquinoline-N-oxide (4NQO), in rat forestomach were examined by an enzymatic 32P-postlabeling assay. Four DNA-adducts were clearly detected in the forestomach after treatment of rats with 4NQO. The sensitivity was 1.9 certain adducts per 10(8) normal nucleotides. On the contrary, no DNA adducts were detected in the forestomach of rats given either a single or repeated oral administration (5 days) of 3-BHA, TBQ or 3-TBOQ. The analyses were carried out under conditions which could detect the DNA-adducts produced by reaction of TBQ with calf thymus DNA in vitro. The results suggest that formation of aromatic adducts in vivo by 3-BHA, TBQ or 3-TBOQ in the rat forestomach-DNA is not evident or at least below the detection limits of the current bioassay.
通过酶促32P后标记试验检测了3 - BHA及其代谢产物叔丁基 - 1,4 - 苯醌（TBQ）和5 - 甲氧基 - 3 - 叔丁基 - 1,2 - 苯醌（3 - TBOQ）在大鼠前胃中形成DNA加合物的情况，以及4 - 硝基喹啉 - N - 氧化物（4NQO）在大鼠前胃中形成DNA加合物的情况。用4NQO处理大鼠后，在前胃中清晰地检测到了四种DNA加合物。灵敏度为每10(8)个正常核苷酸中有1.9个特定加合物。相反，无论是单次还是重复口服（5天）3 - BHA、TBQ或3 - TBOQ的大鼠前胃中均未检测到DNA加合物。分析是在能够检测TBQ与小牛胸腺DNA体外反应产生的DNA加合物的条件下进行的。结果表明，3 - BHA、TBQ或3 - TBOQ在大鼠前胃 - DNA中体内形成芳香族加合物不明显，或者至少低于当前生物测定的检测限。
