Laishes B A, Koropatnick D J, Stich H F
Proc Soc Exp Biol Med. 1975 Sep;149(4):978-82. doi: 10.3181/00379727-149-38938.
The extent of DNA fragmentation induced in lung, kidney, and liver of mice injected with the chemical carcinogens 4-nitroquinoline 1-oxide (4NQO), dimethylnitrosamine (DMN) and the noncarcinogenic 4-aminoquinoline 1-oxide (4AQO) was estimated by the alkaline sucrose gradient technique. A floating of minced lung tissue pieces in the alkaline lysing solution on top of the gradients afforded a gentle method of lung DNA extraction. This technique minimized mechanical shearing of lung DNA and permitted comparisons to be made with liver and kidney DNA sedimentation patterns. The extent of DNA damage induced by 4NQO followed the order: lung, kidney, liver, while that induced by DMN followed the order: liver, kidney, lung. The sites of greatest DNA damage appeared to correlate with sites of high levels of DNA repair synthesis and the sites of tumor induction. No DNA damage was induced by the noncarcinogenic 4-aminoquinoline 1-oxide (4AQO).
通过碱性蔗糖梯度技术评估了注射化学致癌物4-硝基喹啉1-氧化物（4NQO）、二甲基亚硝胺（DMN）以及非致癌性的4-氨基喹啉1-氧化物（4AQO）的小鼠肺、肾和肝脏中DNA片段化的程度。将切碎的肺组织块漂浮在梯度上方的碱性裂解溶液中，提供了一种温和的肺DNA提取方法。该技术使肺DNA的机械剪切最小化，并允许与肝和肾DNA沉降模式进行比较。4NQO诱导的DNA损伤程度顺序为：肺、肾、肝，而DMN诱导的顺序为：肝、肾、肺。DNA损伤最严重的部位似乎与高水平DNA修复合成的部位以及肿瘤诱导部位相关。非致癌性的4-氨基喹啉1-氧化物（4AQO）未诱导DNA损伤。
