Shigenaga M K, Gimeno C J, Ames B N
Division of Biochemistry and Molecular Biology, University of California, Berkeley 94720.
Proc Natl Acad Sci U S A. 1989 Dec;86(24):9697-701. doi: 10.1073/pnas.86.24.9697.
DNA is subject to constant oxidative damage from endogenous oxidants. The oxidized DNA is continuously repaired and the oxidized bases are excreted in the urine. A simple routine analytical procedure is described for urinary 8-hydroxy-2'-deoxyguanosine, an oxidative DNA damage adduct, as an indicator of oxidative damage in humans and rodents. This adduct was purified from human urine and characterized. The described assay employs a series of solid-phase extraction steps that separate 8-hydroxy-2'-deoxyguanosine from other urinary constituents, followed by analysis by gradient reversed-phase HPLC coupled to a dual-electrode high-efficiency electrochemical detection system. Analysis of urine from three species by this method indicates that mice excrete approximately 3.3-fold more 8-hydroxy-2'-deoxyguanosine than humans (582 vs. 178 residues per cell per day), a result that supports the proposal that oxidative damage to DNA increases in proportion to species-specific basal metabolic rates.
DNA 会不断受到内源性氧化剂的氧化损伤。被氧化的 DNA 会持续得到修复，氧化碱基会随尿液排出。本文描述了一种简单的常规分析方法，用于检测尿液中的 8-羟基-2'-脱氧鸟苷（一种氧化 DNA 损伤加合物），以此作为人类和啮齿动物氧化损伤的指标。该加合物从人尿中纯化并进行了表征。所描述的测定方法采用一系列固相萃取步骤，将 8-羟基-2'-脱氧鸟苷与其他尿液成分分离，然后通过梯度反相高效液相色谱与双电极高效电化学检测系统联用进行分析。用该方法对三个物种的尿液分析表明，小鼠排出的 8-羟基-2'-脱氧鸟苷比人类多约 3.3 倍（每天每细胞 582 个与 178 个残基），这一结果支持了以下观点：DNA 的氧化损伤与物种特异性基础代谢率成正比增加。
