中文摘要：

在体内NO和超氧阴离子生成的过氧亚硝酸根离子(ONOO-,peroxynitrite)是一种强氧化性物质,它可以诱导DNA单链断裂使DNA发生损伤。为了探讨ONOO-断裂DNA的作用机理,以质粒DNApBR322为研究对象,采用琼脂糖凝胶和硫代巴比妥酸(TBA)显色反应等方法对ONOO-与DNA的反应进行研究。结果表明ONOO-能明显使DNA发生断裂,而且随着ONOO-浓度的增加,DNA断裂的程度增加,在酸性和中性条件下ONOO-断裂DNA的能力明显高于碱性介质,而CO2对该反应有显著的抑制作用,TBA显色反应进一步证实该反应为自由基机理,其机理为ONOO-与H+形成ONOOH,然后裂解为二氧化氮自由基(·NO2)和羟基自由基(·OH),继而对DNA造成损伤。

英文摘要：

NO reacts with O2·- to yield peroxynitrite (ONOO-), a powerful oxidant in vivo. Peroxynitrite can induce DNA single-stranded breakages. Plasmid pBR322 is used to study the mechanism of DNA strand breakages induced by peroxynitrite. Agarose gel and TBA revealing colour reaction is also developed. The conclusion shows that ONOO- can break DNA strands obviously. The degree of DNA strand breakages is augmenting with the concentration of peroxynitrite increasing. The ability of peroxynitrite breaking DNA strands...