کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10835359 1066090 2005 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Selective quantification of free 3-nitrotyrosine in exhaled breath condensate in asthma using gas chromatography/tandem mass spectrometry
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Selective quantification of free 3-nitrotyrosine in exhaled breath condensate in asthma using gas chromatography/tandem mass spectrometry
چکیده انگلیسی
Reactive nitrogen species can cause oxidative modifications of certain amino acid residues in proteins, notably the modification of tyrosine to 3-nitrotyrosine (3-NT), which is a potentially useful marker of oxidative stress. Since lung diseases are associated with airway inflammation and oxidative stress, quantification of 3-NT in exhaled breath condensate (EBC) may provide a non-invasive means for monitoring ongoing inflammatory processes. 3-NT-like immunoreactivity has previously been detected in EBC, but no definitive evidence for the presence of 3-NT in EBC is available. Here, a method based on gas chromatography/negative ion chemical ionization/tandem mass spectrometry was established for the quantification of free 3-NT in EBC. The detection limit was 0.56 pM (corresponding to 3.0 amol μl−1 sample injected) and the method was found to give linear results (r2 > 0.999) in the concentration range of 0-5.0 nM. The coefficient of variation (CV) for within-day and between-day precision were 11 and 12%, respectively. No artifactual nitration was observed during sample processing. The method was applied to study subjects with asthma (n = 8), and healthy subjects (n = 10), but only a slight non-significant increase in 3-NT levels was found in the former group (median [interquartile ranges]; 99 [50-547] amol s−1 vs. 75 [35-147] amol s−1). No correlation with exhaled nitric oxide (NO), pulmonary function or EBC levels of total protein was observed. The 3-NT levels were much lower compared to previously reported levels, based on immunochemical measurements. The method does not allow the simultaneous quantification of tyrosine in samples.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nitric Oxide - Volume 13, Issue 2, September 2005, Pages 134-144
نویسندگان
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