• 主题
高级搜索  >
历史搜索 清空历史
首页> 美国卫生研究院文献>Biochemical Journal >Peroxynitrite-mediated formation of free radicals in human plasma: EPR detection of ascorbyl albumin-thiyl and uric acid-derived free radicals.
【2h】

Peroxynitrite-mediated formation of free radicals in human plasma: EPR detection of ascorbyl albumin-thiyl and uric acid-derived free radicals.

机译：过氧亚硝酸盐介导的人血浆中自由基的形成：EPR检测抗坏血酸白蛋白-噻吩和尿酸衍生的自由基。

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务，本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文，但由于OA文献来源多样且变更频繁，仍可能出现获取不到、文献不完整或与标题不符等情况，如果获取不到我们将提供退款服务。请知悉。
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Formation of peroxynitrite by the fast reaction between nitric oxide and superoxide anion may represent a critical control point in cells producing both species, leading to either down-regulation of the physiological effects of superoxide anion and nitric oxide by forming an inert product, nitrate, or to potentiation of their toxic effects by oxidation of nearby molecules by peroxynitrite. (The term peroxynitrite is used to refer to the sum of all possible forms of peroxynitrite anion and peroxynitrous acid unless otherwise specified.) In this report we demonstrate that, in spite of all the antioxidant defences present in human plasma, its interaction with peroxynitrite leads to generation of free radical intermediates such as (i) the ascorbyl radical, detected by direct EPR, (ii) the albumin-thiyl radical, detected by spin-trapping experiments with both N-tert-butyl-alpha-phenylnitrone and 5,5-dimethyl-1-pyrroline N-oxide (DMPO), and (iii) a uric acid-derived free radical, detected as the DMPO radical adduct in plasma whose thiol groups were previously blocked with 5,5-dithiobis-(2-nitrobenzoic acid). The identity of the latter adduct was confirmed by parallel experiments demonstrating that it is not detectable in plasma pretreated with uricase, whereas it is formed in incubations of peroxynitrite with uric acid. Peroxynitrite-mediated oxidations were also followed by oxygen consumption and ascorbate and plasma-thiol depletion. Our results support the view that peroxynitrite-mediated one-electron oxidation of biomolecules may be an important event in its cytotoxic mechanism. In addition, the data have methodological implications by providing support for the use of EPR methodologies for monitoring both free radical reactions and ascorbate concentrations in biological fluids.
机译：一氧化氮与超氧阴离子之间快速反应形成的过氧亚硝酸盐可能代表着产生这两种物质的细胞中的关键控制点，导致通过形成惰性产物硝酸盐或超氧化物阴离子和一氧化氮的生理作用下调。通过过亚硝酸盐氧化附近的分子来增强其毒性作用。 （除非另有说明，术语过氧亚硝酸盐用于表示过氧亚硝酸盐阴离子和过氧亚硝酸的所有可能形式的总和。）在本报告中，我们证明，尽管人血浆中存在所有抗氧化剂防御作用，但其与过氧亚硝酸盐铅的相互作用生成自由基中间体，例如（i）通过直接EPR检测的抗坏血酸基，（ii）通过N-叔丁基-α-苯基硝酮和5,5的自旋阱实验检测的白蛋白-噻吩基-二甲基-1-吡咯啉N-氧化物（DMPO）和（iii）尿酸衍生的自由基，在血浆中的DMPO自由基加合物中被检测出，该血浆中的巯基先前已被5,5-二硫代双-（2-硝基苯甲酸）阻断酸）。后者的加合物的身份通过平行实验证实，证明在尿酸酶预处理的血浆中无法检测到，而在过氧亚硝酸盐与尿酸的孵育中形成。过氧亚硝酸盐介导的氧化还伴随着氧气的消耗，抗坏血酸盐和血浆硫醇的消耗。我们的结果支持这样的观点，即过氧亚硝酸盐介导的生物分子的单电子氧化可能是其细胞毒性机制中的重要事件。此外，这些数据还通过支持EPR方法用于监测生物液体中的自由基反应和抗坏血酸浓度而具有方法学意义。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号