Larramendy M, Mello-Filho A C, Martins E A, Meneghini R
Mutat Res. 1987 May;178(1):57-63. doi: 10.1016/0027-5107(87)90086-8.
When Chinese hamster fibroblasts were exposed to hydrogen peroxide or to a system consisting of xanthine oxidase and hypoxanthine, which generates superoxide anion plus hydrogen peroxide, sister-chromatid exchanges (SCEs) were formed in a dose-dependent manner. When the iron-complexing agent o-phenanthroline was present in the medium, however, the production of these SCEs was completely inhibited. This fact indicates that the Fenton reaction: Fe2+ + H2O2----OH0 + OH- + Fe3+ is responsible for the production of SCEs. When O2- and H2O2 were generated inside the cell by incubation with menadione, the production of SCE was prevented by co-incubation with copper diisopropylsalicylate, a superoxide dismutase mimetic agent. The most likely role of O2- is as a reducing agent of Fe3+: O2- + Fe3+----Fe2+ + O2, so that the sum of this and the Fenton reaction, i.e., the iron-catalyzed Haber-Weiss reaction, provides an explanation for the active oxygen species-induced SCE: H2O2 + O2(-)----OH- + OH0 + O2. According to this view, the OH radical thus produced is the agent which ultimately causes SCE. These results are discussed in comparison with other mechanisms previously proposed for induction of SCE by active oxygen species.
当中国仓鼠成纤维细胞暴露于过氧化氢或由黄嘌呤氧化酶和次黄嘌呤组成的体系（该体系产生超氧阴离子加过氧化氢）时，姐妹染色单体交换（SCEs）以剂量依赖的方式形成。然而，当培养基中存在铁络合剂邻菲罗啉时，这些SCEs的产生被完全抑制。这一事实表明，芬顿反应：Fe2+ + H2O2→OH• + OH- + Fe3+ 是SCEs产生的原因。当通过与甲萘醌孵育在细胞内产生O2-和H2O2时，与超氧化物歧化酶模拟剂二异丙基水杨酸铜共同孵育可防止SCE的产生。O2-最可能的作用是作为Fe3+的还原剂：O2- + Fe3+→Fe2+ + O2，因此，这一反应与芬顿反应的总和，即铁催化的哈伯-维伊斯反应，为活性氧诱导的SCE提供了解释：H2O2 + O2-→OH- + OH• + O2。根据这一观点，由此产生的OH自由基是最终导致SCE的介质。将这些结果与先前提出的活性氧诱导SCE的其他机制进行了比较讨论。
