کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10550154 | 967024 | 2005 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Determination of 3-nitrotyrosine in human urine at the basal state by gas chromatography-tandem mass spectrometry and evaluation of the excretion after oral intake
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
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چکیده انگلیسی
3-Nitrotyrosine (NO2Tyr) is a potential biomarker of reactive-nitrogen species (RNS) including peroxynitrite. 3-Nitrotyrosine occurs in human plasma in its free and protein-associated forms and is excreted in the urine. Measurement of 3-nitrotyrosine in human plasma is invasive and associated with numerous methodological problems. Recently, we have described an accurate method based on gas chromatography (GC)-tandem mass spectrometry (MS) for circulating 3-nitrotyrosine. The present article describes the extension of this method to urinary 3-nitrotyrosine. The method involves separation of urinary 3-nitrotyrosine from nitrite, nitrate and l-tyrosine by HPLC, preparation of the n-propyl-pentafluoropropionyltrimethylsilyl ether derivatives of endogenous 3-nitrotyrosine and the internal standard 3-nitro-l-[2H3]tyrosine, and GC-tandem MS quantification in the selected-reaction monitoring mode under negative-ion chemical ionization conditions. In urine of ten apparently healthy volunteers (years of age, 36.5 ± 7.2) 3-nitrotyrosine levels were determined to be 8.4 ± 10.4 nM (range, 1.6-33.2 nM) or 0.46 ± 0.49 nmol/mmol creatinine (range, 0.05-1.30 nmol/mmol creatinine). The present GC-tandem MS method provides accurate values of 3-nitrotyrosine in human urine at the basal state. After oral intake of 3-nitro-l-tyrosine by a healthy volunteer (27.6 μg/kg body weight) 3-nitro-l-tyrosine appeared rapidly in the urine and was excreted following a biphasic pharmacokinetic profile. Approximately one third of administered 3-nitro-l-tyrosine was excreted within the first 8 h. The suitability of the non-invasive measurement of urinary 3-nitrotyrosine as a method of assessment of oxidative stress in humans remains to be established.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Chromatography B - Volume 827, Issue 1, 15 November 2005, Pages 146-156
Journal: Journal of Chromatography B - Volume 827, Issue 1, 15 November 2005, Pages 146-156
نویسندگان
Dimitrios Tsikas, Anja Mitschke, Maria-Theresia Suchy, Frank-Mathias Gutzki, Dirk O. Stichtenoth,