Nakatsuru Y, Nemoto N, Nakagawa K, Masahito P, Ishikawa T
Carcinogenesis. 1987 Aug;8(8):1123-7. doi: 10.1093/carcin/8.8.1123.
O6-Methylguanine DNA methyltransferase (O6-MT) is considered to play an important role in the repair of alkylating carcinogen-induced lesions in a wide range of mammalian species. Fish are used widely in cancer research, one advantage being their high sensitivity to a variety of alkylating agents. To throw light on the mechanisms of DNA repair in the hitherto uninvestigated fish group, O6-MT activity was measured in liver from eight fish species belonging to six classes. Levels of O6-MT activity comparable with mouse values were found in liver of Japanese medaka (Oryzias latipes). Relatively low, but appreciable, levels of O6-MT activity were also observed in the other seven species examined. No adaptive increase in enzyme activity could be established in liver of rainbow trout following chronic dimethylnitrosamine pretreatment.
O6-甲基鸟嘌呤DNA甲基转移酶（O6-MT）被认为在多种哺乳动物物种中修复烷基化致癌物诱导的损伤过程中发挥着重要作用。鱼类在癌症研究中被广泛应用，其优点之一是它们对多种烷基化剂具有高度敏感性。为了阐明迄今尚未研究的鱼类群体中的DNA修复机制，我们测定了六个纲的八种鱼类肝脏中的O6-MT活性。在日本青鳉（Oryzias latipes）的肝脏中发现了与小鼠水平相当的O6-MT活性水平。在其他七种被检测的物种中也观察到了相对较低但相当可观的O6-MT活性水平。在慢性二甲基亚硝胺预处理后，虹鳟鱼肝脏中未发现酶活性的适应性增加。
