Red cell membrane and plasma linoleic acid nitration products: Synthesis, clinical identification, and quantitation
Red cell membrane and plasma linoleic acid nitration products: Synthesis, clinical identification, and quantitation
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DOI：
10.1073/pnas.0402587101
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发表时间：
2004-08-10
影响因子：
11.1
通讯作者：
Freeman, BA
中科院分区：
文献类型：
--
作者：
Baker, PRS;Schopfer, FJ;Freeman, BA
一氧化氮 ((NO)-N-.) 及其反应性代谢物介导 DNA 碱基、氨基酸和脂质的氧化、硝化和亚硝化。在这里，我们报告了亚油酸（LNO2）的两种烯丙基硝基衍生物的结构表征和定量，这两种衍生物以游离和酯化形式存在于人红细胞膜和血浆脂质中。合成了 LNO2 异构体 10-硝基-9-顺,12-顺-十八碳二烯酸和 12-硝基-9-顺,12-顺-十八碳二烯酸，并根据色谱洗脱和质谱特性与红细胞和血浆 LNO2 物种进行比较。合成 LNO2 异构体碰撞诱导的解离断裂模式与红细胞和血浆中发现的两种最常见的 LNO2 位置异构体相同。通过使用 [C-13]LNO2 作为内标，无红细胞和酯化 LNO2 含量分别为 50 +/- 17 和 249 +/- 104 nM。血浆中游离 LNO2 和酯化 LNO2 含量分别为 79 +/- 35 和 550 +/- 275 nM。因此，硝化脂肪酸代表了脉管系统中最大的生物活性氮氧化物库，净 LNO2 浓度为 477 +/- 128 nM（不包括血沉棕黄层细胞）。这些观察结果证实，健康人体中发生的基础氧化和硝化条件足以诱导大量的膜和脂蛋白脂肪酸硝化。鉴于 LNO2 能够介导 cGMP 和非 cGMP 依赖性信号反应，脂肪酸硝化产物是代表 No- 收敛的物种。和氧化脂质细胞信号传导途径。
Nitric oxide ((NO)-N-.) and its reactive metabolites mediate the oxidation, nitration, and nitrosation of DNA bases, amino acids, and lipids. Here, we report the structural characterization and quantitation of two allylic nitro derivatives of linoleic acid (LNO2), present as both free and esterified species in human red cell membranes and plasma lipids. The LNO2 isomers 10-nitro-9-cis,12-cis-octadecadienoic acid and 12-nitro-9-cis,12-cis-octadecadienoic acid were synthesized and compared with red cell and plasma LNO2 species based on chromatographic elution and mass spectral properties. Collision-induced dissociation fragmentation patterns from synthetic LNO2 isomers were identical to those of the two most prevalent LNO2 positional isomers found in red cells and plasma. By using [C-13]LNO2 as an internal standard, red cell free and esterified LNO2 content was 50 +/- 17 and 249 +/- 104 nM, respectively. The free and esterified LNO2 content of plasma was 79 +/- 35 and 550 +/- 275 nM, respectively. Nitrated fatty acids, thus, represent the single largest pool of bioactive oxides of nitrogen in the vasculature, with a net LNO2 concentration of 477 +/- 128 nM, excluding buffy coat cells. These observations affirm that basal oxidative and nitrating conditions occur in healthy humans to an extent that is sufficient to induce abundant membrane and lipoprotein-fatty acid nitration. Given that LNO2 is capable of mediating cGMP and non-cGMP-dependent signaling reactions, fatty acid nitration products are species representing the convergence of No-. and oxygenated lipid cell-signaling pathways.