Linked Life Data

15607702

Source:http://linkedlifedata.com/resource/pubmed/id/15607702

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2004-12-20
pubmed:abstractText
L-Tyrosine and L-tyrosine residues in proteins are attacked by various reactive-nitrogen species (RNS) including peroxynitrite to form 3-nitrotyrosine (NO(2)Tyr) and protein-associated 3-nitrotyrosine (NO(2)TyrProt). Circulating NO(2)Tyr and NO(2)TyrProt have been suggested and are widely used as biomarkers of oxidative stress in humans. In this article the mass spectrometry (MS)-based analytical methods recently reported for the quantification of circulating levels of NO(2)Tyr and NO(2)TyrProt are discussed. These methodologies differ in sensitivity, selectivity, specificity and accessibility to interferences with the latter mainly arising from artifactual formation of NO(2)Tyr and NO(2)TyrProt during sample treatment such as acidification and chemical derivatization. Application of these methodologies to healthy normal humans revealed basal circulating levels for NO(2)Tyr which range between 0.7 and 64 nM, i.e. by two orders of magnitude. Application of gas chromatography-tandem mass spectrometry (GC-tandem MS) methods by two independent research groups by using two different protocols to avoid artifactual nitration of L-tyrosine revealed almost identical mean plasma levels of the order of 1.0 nM in healthy humans. The lower limits of quantitation (LOQ) of these methods were 0.125 and 0.3n M, respectively. This order of magnitude for basal NO(2)Tyr is supported by two liquid chromatography-tandem mass spectrometry (LC-tandem MS) methods with LOQ values of 4.4 and 1.4 nM. On the basis of the data provided by GC-tandem MS and LC-tandem MS the use of a range of 0.5-3 nM for NO(2)Tyr and of 0.6 pmol/mg plasma protein or a molar ratio of 3-nitrotyrosine to tyrosine in plasma proteins of the order of 1:10(6) for NO(2)TyrProt in plasma of healthy humans as reference values appear reasonably justified. Recently reported clinical studies involving 3-nitrotyrosine as a biomarker of oxidative stress are discussed in particular from the analytical point of view.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1570-0232
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
814
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Recent methodological advances in the mass spectrometric analysis of free and protein-associated 3-nitrotyrosine in human plasma.
pubmed:affiliation
Institute of Clinical Pharmacology, Hannover Medical School, Carl-Neuberg-Strasse 1, D-30625 Hannover, Germany. tsikas.dimitros@mh-hannover.de
pubmed:publicationType
Journal Article, Review