Quantitation of Biomarkers of Oxidative Stress by NICI-MS

1996年，在NIEHS举办了一个关于测量人类氧化应激的讲习班。 人们普遍认为，开展一项比较从同一样本中测量的各种氧化应激标志物的研究是有价值的。 一种这样的标志物是F2 a-异前列烷，其通过NICI-MS定量。异前列烷是类胡萝卜素化合物，其是由于膜磷脂中花生四烯酸的化学氧化而不是酶促氧化而产生的。异前列烷已被证明具有有效的生物活性，许多研究表明它们是氧化应激动物模型中脂质过氧化的准确标志物。 8-iso-F2 a-异前列烷是大多数研究中定量的特定异构体。 尽管最近有证据表明该化合物的某些环氧合酶催化形成，但酶促途径的作用似乎很小，主要是游离脂质氧化而不是膜结合脂质氧化的结果。 分析该化合物的标准方法是在负离子化学电离条件下通过五氟苄基酯三甲基甲硅烷基衍生物的GC/MS。 我们在这项研究中的作用是建立内部方法，用于测量生理样品中的异前列烷，并与NIEHS/NIH的其他小组合作提供这种能力。还启动了一些其他研究，包括测量异前列烷作为氧化应激指标。妇女的酒精研究P.泰勒（NCI）/D。Baer，J. Judd（美国农业部）O.S.相关性突变（T. Devereaux，LMC）在化学诱导的小鼠肝细胞腺瘤和癌中鉴定出突变，假设突变是间接DNA损伤的结果，可能来自OS？氧化损伤机制小组-一个跨实验室小组，对用特定有毒物质处理引起的组织非遗传毒性损伤的各种标志物进行比较。 目的是比较哪种类型的毒素引发哪种类型的损伤，以更好地了解其毒性的机制。 我们为本研究提供异前列烷分析。

In 1996 a workshop on Measurement of Oxidative Stress in Humans was held at NIEHS. There was a general consensus that it would be valuable to mount a study comparing various markers of oxidative stress measured from the same sample. One such marker is F2a-isoprostane which is quantitated by NICI-MS. Isoprostanes are prostaglandin-like compounds that are produced as a result of the chemical rather than enzymatic oxidation of arachidonic acid in membrane phospholipids. The isoprostanes have been shown to possess potent biological activity, and a number of studies have shown them to be accurate markers of lipid peroxidation in animal models of oxidative stress. The 8-iso-F2a-isoprostane has been the specific isomer quantified in most studies. Although there is recent evidence for some cyclooxygenase catalyzed formation of this compound, the contribution of the enzymatic pathway has appeared to be minor and primarily the result of oxidation of free lipid rather than membrane-bound lipid. The standard method for analyzing this compound is by GC/MS of the pentafluorobenzyl ester trimethylsilyl derivative under negative ion chemical ionization conditions. Our role in this study has been to establish methodology in-house for the measurement of isoprostanes in physiological samples and to provide this capability in collaboration with other groups at NIEHS/NIH. A number of other studies involving measurement of isoprostanes as an indicator of oxidative stress have also been initiated. Women's Alcohol Study P. Taylor (NCI)/D. Baer, J. Judd (USDA)Correlation of O.S. with mutations (T. Devereaux, LMC)identified mutations in chemically induced mouse hepatocellular adenomas and carcinomas hypothesize mutations are the result of indirect DNA damage, possibly from O.S.?Mechanisms of oxidative damage group - A cross-laboratory group interested in comparing various markers of non-genotoxic damage to tissues as a result of treatment with specific toxic substances. The goal is to compare which types of toxins initiate which types of damage to provide a better mechanistic understanding of their toxicity. We are providing isoprostane analyses for this study.