Reactive oxygen species
Reactive oxygen species
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DOI：
10.1097/01.ccm.0000186787.64500.12
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发表时间：
2005-12-01
影响因子：
8.8
通讯作者：
Bayir, H
中科院分区：
文献类型：
--
作者：
Bayir, H
自由基被定义为含有一个或多个未成对电子的任何物质（1）。活性氧（ROS）是一个集合术语，包括氧自由基，如超氧化物（O2）、羟基（OH）、过氧基（RO 2）和氢过氧基（HO 2）自由基，以及某些非自由基氧化剂，如过氧化氢（H2 O2）、次氯酸（HOCl）和臭氧（O3），它们可以容易地转化为自由基（1）。ROS与脓毒症的发病机制有关（2）。然而，ROS也在正常代谢过程中产生，并参与酶促反应、线粒体电子传递、信号转导、核转录因子的活化、基因表达以及中性粒细胞和巨噬细胞的抗菌作用。这种还原环境由抗氧化酶和物质的作用维持，如超氧化物歧化酶（SOD）、过氧化氢酶、谷胱甘肽过氧化物酶、谷胱甘肽、抗坏血酸盐（维生素C）、α-生育酚（维生素E）和硫氧还蛋白。氧化还原状态的改变和暴露于氧化剂导致的抗氧化剂的消耗导致氧化应激和由此产生的氧化损伤。
A free radical is defined as any species that contains one or more unpaired electrons (1). Reactive oxygen species (ROS) is a collective term that includes both oxygen radicals, such as superoxide (O2 J), hydroxyl (OH), peroxyl (RO2), and hydroperoxyl (HO2) radicals, and certain nonradical oxidizing agents, such as hydrogen peroxide (H2O2), hypochlorous acid (HOCl), and ozone (O3), that can be converted easily to into radicals (1). ROS are implicated in the pathogenesis of sepsis (2). However, ROS are also produced during normal metabolism and are involved in enzymatic reactions, mitochondrial electron transport, signal transduction, activation of nuclear transcription factors, gene expression, and the antimicrobial action of neutrophils and macrophages.In general, the reducing environment inside cells helps to prevent free radicalmediated damage. This reducing environment is maintained by the action of antioxidant enzymes and substances, such as superoxide dismutase (SOD), catalase, glutathione peroxidase, glutathione, ascorbate (vitamin C), α-tocopherol (vitamin E), and thioredoxin. Alterations in the redox state and depletion of antioxidants by exposure to oxidants lead to oxidative stress and resultant oxidative injury.