Quantitation of 8-oxoguanine and strand breaks produced by four oxidizing agents
Quantitation of 8-oxoguanine and strand breaks produced by four oxidizing agents
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DOI：
10.1021/tx960102w
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发表时间：
1997-04-01
影响因子：
4.1
通讯作者：
Dedon, PC
中科院分区：
文献类型：
--
作者：
Kennedy, LJ;Moore, K;Dedon, PC
内源性或暴露于环境化学品和电离辐射产生的活性氧可诱导广泛的DNA损伤。与不同氧化剂相关的各种化学物质表明，每种氧化剂都会产生独特的DNA损伤产物谱。为了扩大我们的努力，遗传毒素化学与DNA损伤，我们测量了链断裂和8-氧代鸟嘌呤（8-oxoG）的DNA暴露后，γ-辐射，Fe（II）-EDTA/H2 O2，Cu（II）H2 O2，和过氧亚硝酸盐在接近生理相关性的浓度。我们发现，8-oxoG链断裂的比例变化超过10倍，这取决于氧化剂：类似于0.4的Cu（II）H2 O2和过氧亚硝酸盐和类似于0.03的Fe（II）-EDTA/H2 O2和γ-辐射。在Cu（II）H2 O2的情况下，发现对于不同的Cu（II）浓度，8-oxoG和链断裂的相对比例变化超过2倍（0.14-0.37），与其他研究一致。我们能够检测8-oxoG形成过氧亚硝酸盐通过使用低过氧亚硝酸盐浓度结合灵敏的免疫亲和/KPLC-ECD方法。8-oxoG相对于链断裂所产生的过氧亚硝酸盐的水平是高于所产生的Fe（II）-EDTA/H2 O2和γ-辐射，这是一致的改变的反应性或可访问性的非羟基自由基物种所产生的过氧亚硝酸盐。
Reactive oxygen species, produced endogenously or by exposure to environmental chemicals and ionizing radiation, induce a wide range of DNA lesions. The variety of chemistries associated with different oxidants suggests that each will produce a unique spectrum of DNA damage products. To extend our efforts to relate genotoxin chemistry to DNA damage, we measured both strand breaks and 8-oxoguanine (8-oxoG) in DNA after exposure to gamma-radiation, Fe(II)-EDTA/H2O2, Cu(II)H2O2, and peroxynitrite at concentrations approaching physiological relevance. We found that the ratio of 8-oxoG to strand breaks varied more than 10-fold depending on the oxidizing agent: similar to 0.4 for Cu(II)H2O2 and peroxynitrite and similar to 0.03 for Fe(II)-EDTA/H2O2 and gamma-radiation. In the case of Cu(II)H2O2, the relative proportion of 8-oxoG and strand breaks was found to vary more than 2-fold (0.14-0.37) for different Cu(II) concentrations, consistent with other studies. We were able to detect 8-oxoG formation by peroxynitrite by using low peroxynitrite concentrations in conjunction with a sensitive immunoaffinity/KPLC-ECD methodology. The level of 8-oxoG relative to strand breaks produced by peroxynitrite was higher than that produced by Fe(II)-EDTA/H2O2 and gamma-radiation, which is consistent with the altered reactivity or accessibility of a non-hydroxyl radical species produced by peroxynitrite.