Norman C A, Lambert I B, Davison L M, Bryant D W, McCalla D R
Department of Biochemistry, McMaster University, Hamilton, Ontario, Canada.
Carcinogenesis. 1989 Jul;10(7):1323-7. doi: 10.1093/carcin/10.7.1323.
Formation of DNA adducts, following treatment of primary rabbit tracheal epithelial cells (RTEC) with 1,8-dinitropyrene (1,8-DNP) and its partially reduced derivative, 1-nitro-8-nitrosopyrene (1,8-NONO2), was examined using the 32P-post-labelling technique. Treatment of aerobic cells with 1,8-DNP or 1,8-NONO2 produced qualitatively similar results. Cochromatography showed that the major adduct observed corresponded to the major adduct seen following treatment of poly(dG.dC) with N-hydroxyl-1-amino-8-nitropyrene, generated from 1,8-NONO2. A minor adduct migrated to the same area on the TLC plate as the major compound observed following a similar treatment with poly(dA.dT). Relative adduct labelling (RAL) values were consistently an order of magnitude higher with 1,8-NONO2 than with 1,8-DNP, suggesting that reduction of a nitro group of 1,8-DNP to a nitroso group may be a rate-limiting step in the cells. In studies on the formation and persistence of the 1,8-NONO2 adduct in RTEC maximum binding was observed at 1 h. Fifteen hours later the RAL value was less than 15% of this maximum level.
采用³²P后标记技术，检测了原代兔气管上皮细胞（RTEC）经1,8 - 二硝基芘（1,8 - DNP）及其部分还原衍生物1 - 硝基 - 8 - 亚硝基芘（1,8 - NONO₂）处理后DNA加合物的形成情况。用1,8 - DNP或1,8 - NONO₂处理需氧细胞产生了定性相似的结果。共色谱分析表明，观察到的主要加合物与用1,8 - NONO₂产生的N - 羟基 - 1 - 氨基 - 8 - 硝基芘处理聚（dG.dC）后看到的主要加合物相对应。一种次要加合物在薄层层析板上迁移到与用聚（dA.dT）进行类似处理后观察到的主要化合物相同的区域。相对加合物标记（RAL）值用1,8 - NONO₂始终比用1,8 - DNP高一个数量级，这表明1,8 - DNP的一个硝基还原为亚硝基可能是细胞中的限速步骤。在关于RTEC中1,8 - NONO₂加合物形成和持久性的研究中，在1小时时观察到最大结合。15小时后，RAL值小于该最大水平的15%。
