γ-Tocopherol supplementation inhibits protein nitration and ascorbate oxidation in rats with inflammation
γ-Tocopherol supplementation inhibits protein nitration and ascorbate oxidation in rats with inflammation
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DOI：
10.1016/s0891-5849(02)01091-2
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发表时间：
2002-12-01
影响因子：
7.4
通讯作者：
Ames, BN
中科院分区：
文献类型：
--
作者：
Jiang, Q;Lykkesfeldt, J;Ames, BN
γ-生育酚(GammaT)通过捕获活性氮氧化物形成稳定的加合物5-硝基-GammaT来补充α-生育酚(AlphaT)[Christen等人，PNAS 94：3217-3222；1997]。这一观察导致了目前的研究，我们研究了在酵母多糖诱导的急性腹膜炎前后，补充GammaT对血浆和组织中维生素C、维生素E和蛋白质硝化的影响。雄性Fischer 344大鼠用普通饲料喂养4周，基础饲料中添加32 mg/kg的γ-GAMA，或在相同的饲料中添加类似90 mg/kg的d-GAMMA T。添加酵母多糖可显著提高对照组动物血浆、肝脏和肾脏中的γ-T水平，而不影响αT、总αT+γ-T和维生素C的含量。添加GammaT显著抑制了肾脏的蛋白质硝化和抗坏血酸氧化，肾脏3-硝基酪氨酸和脱氢抗坏血酸分别减少了29%和56%。补充剂显著减少了炎症引起的血浆(38%)和肾脏(20%)维生素C的损失。酵母多糖处理的动物的血浆和组织中的GammaT显著高于未处理的配对喂养的对照组，并且补充酵母多糖强烈地加剧了GammaT的升高。相比之下，αT对酵母多糖处理的反应没有显著变化。在未经处理的对照组动物中，补充GammaT降低了肾脏中3-硝基酪氨酸的基础水平，并缓解了饥饿导致的所有组织中维生素C的变化。我们的研究首次提供了体内证据表明，在基础水平较高的αT大鼠中，适量补充γ-T可减轻炎症介导的损伤，并在饥饿诱导的应激过程中节省维生素C，而不影响αT。(C)2002年爱思唯尔科学公司。
gamma-Tocopherol (gammaT) complements alpha-tocopherol (alphaT) by trapping reactive nitrogen oxides to form a stable adduct, 5-nitro-gammaT [Christen et al., PNAS 94:3217-3222; 1997]. This observation led to the current investigation in which we studied the effects of gammaT supplementation on plasma and tissue vitamin C, vitamin E, and protein nitration before and after zymosan-induced acute peritonitis. Male Fischer 344 rats were fed for 4 weeks with either a normal chow diet with basal 32 mg gammaT/kg, or the same diet supplemented with similar to90mg d-gammaT/kg. Supplementation resulted in significantly higher levels of gammaT in plasma, liver, and kidney of control animals without affecting alphaT, total alphaT + gammaT or vitamin C. Intraperitoneal injection of zymosan caused a marked increase in 3-nitrotyrosine and a profound decline in vitamin C in all tissues examined. Supplementation with gammaT significantly inhibited protein nitration and ascorbate oxidation in the kidney, as indicated by the 29% and 56% reduction of kidney 3-nitrotyrosine and dehydroascorbate, respectively. Supplementation significantly attenuated inflammation-induced loss of vitamin C in the plasma (38%) and kidney (20%). Zymosan-treated animals had significantly higher plasma and tissue gammaT than nontreated pair-fed controls, and the elevation of gammaT was strongly accentuated by the supplementation. In contrast, alphaT did not significantly change in response to zymosan treatment. In untreated control animals, gammaT supplementation lowered basal levels of 3-nitrotyrosine in the kidney and buffered the starvation-induced changes in vitamin C in all tissues examined. Our study provides the first in vivo evidence that in rats with high basal amounts of alphaT, a moderate gammaT supplementation attenuates inflammation-mediated damage, and spares vitamin C during starvation-induced stress without affecting alphaT. (C) 2002 Elsevier Science Inc.