Ames B N
Department of Biochemistry, University of California, Berkeley 94720.
Free Radic Res Commun. 1989;7(3-6):121-8. doi: 10.3109/10715768909087933.
Progress in identifying the important endogenous processes damaging DNA and developing methods to assay this damage in individuals is presented. This approach may aid studies on modulation of cancer and aging. The endogenous background level of oxidant-induced DNA damage in vivo has been assayed by measuring 8-hydroxydeoxyguanosine (oh8dG), thymine glycol and thymidine glycol in urine and oh8dG in DNA. oh8dG is one of about 20 adducts found on oxidizing DNA, e.g., by radiation. The level of oxidative DNA damage as measured by oh8dG in normal rat liver is shown to be extensive, especially in mtDNA (1/130,000 bases in nuclear DNA and 1/8,000 bases in mitochondrial DNA). We also discuss three hitherto unrecognized antioxidants in man.
本文介绍了在识别损害DNA的重要内源性过程以及开发个体DNA损伤检测方法方面取得的进展。这种方法可能有助于癌症和衰老调控的研究。通过测量尿液中的8-羟基脱氧鸟苷（oh8dG）、胸腺嘧啶乙二醇和胸苷乙二醇以及DNA中的oh8dG，已测定了体内氧化剂诱导的DNA损伤的内源性背景水平。oh8dG是在氧化DNA（例如通过辐射）时发现的约20种加合物之一。正常大鼠肝脏中通过oh8dG测量的氧化DNA损伤水平很高，尤其是在线粒体DNA中（核DNA中为1/130,000个碱基，线粒体DNA中为1/8,000个碱基）。我们还讨论了人体内三种迄今未被认识的抗氧化剂。
