Ishikawa T, Takayama S, Ide F
Cancer Res. 1980 Aug;40(8 Pt 1):2898-902.
A system in which tracheal organ culture of inbred F344 rats was used in combination with autoradiography was developed for quantitative measurement of DNA repair synthesis in tracheal epithelial cells. Small sections of trachea in short-term organ culture were treated with various carcinogens plus [methyl-3H]thymidine. Significant numbers of grains, indicating DNA repair, were detected on the nuclei of epithelial cells of tracheal sections treated with carcinogens, and the numbers were proportioned to the concentrations of the carcinogens. The nuclear [methyl-3H]thymidine labeling index (S-phase index) was approximately 0.02, and this did not interfere appreciably with quantitative grain counting. This autoradiographic method is suitable for quantitative measurement of DNA repair synthesis in epithelial cells of the trachea in conditions mimicking those in vivo. These results suggest the potential use of this system for studies on the mechanism of carcinogenesis at a cellular level in keeping with recent biochemical studies on metabolism of carcinogens in respiratory organs in culture. The system may also be useful for screening environmental chemicals suspected of damaging DNA of the respiratory organs in relation to lung carcinogenesis.
我们开发了一种系统，该系统将近交系F344大鼠的气管器官培养与放射自显影相结合，用于定量测量气管上皮细胞中的DNA修复合成。短期器官培养中的小块气管用各种致癌物加[甲基-³H]胸腺嘧啶核苷处理。在用致癌物处理的气管切片的上皮细胞核上检测到大量表明DNA修复的银粒，且银粒数量与致癌物浓度成比例。细胞核[甲基-³H]胸腺嘧啶核苷标记指数（S期指数）约为0.02，这对定量银粒计数没有明显干扰。这种放射自显影方法适用于在模拟体内条件下定量测量气管上皮细胞中的DNA修复合成。这些结果表明，该系统有可能用于细胞水平上致癌机制的研究，这与近期关于培养的呼吸器官中致癌物代谢的生化研究一致。该系统也可能有助于筛选怀疑与肺癌发生有关的、对呼吸器官DNA有损伤作用的环境化学物质。
