Linked Life Data

16971501

Source:http://linkedlifedata.com/resource/pubmed/id/16971501

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2007-1-12
pubmed:abstractText
Dihydroethidium (DHE) is a widely used sensitive superoxide (O2(*-)) probe. However, DHE oxidation yields at least two fluorescent products, 2-hydroxyethidium (EOH), known to be more specific for O2(*-), and the less-specific product ethidium. We validated HPLC methods to allow quantification of DHE products in usual vascular experimental situations. Studies in vitro showed that xanthine/xanthine oxidase, and to a lesser degree peroxynitrite/carbon dioxide system led to EOH and ethidium formation. Peroxidase/H2O2 but not H2O2 alone yielded ethidium as the main product. In vascular smooth muscle cells incubated with ANG II (100 nM, 4 h), we showed a 60% increase in EOH/DHE ratio, prevented by PEG-SOD or SOD1 overexpression. We further validated a novel DHE-based NADPH oxidase assay in vascular smooth muscle cell membrane fractions, showing that EOH was uniquely increased after ANG II. This assay was also adapted to a fluorescence microplate reader, providing results in line with HPLC results. In injured artery slices, shown to exhibit increased DHE-derived fluorescence at microscopy, there was approximately 1.5- to 2-fold increase in EOH/DHE and ethidium/DHE ratios after injury, and PEG-SOD inhibited only EOH formation. We found that the amount of ethidium product and EOH/ethidium ratios are influenced by factors such as cell density and ambient light. In addition, we indirectly disclosed potential roles of heme groups and peroxidase activity in ethidium generation. Thus HPLC analysis of DHE-derived oxidation products can improve assessment of O2(*-) production or NADPH oxidase activity in many vascular experimental studies.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0363-6143
pubmed:author
pubmed:issnType
Print
pubmed:volume
292
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C413-22
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Analysis of DHE-derived oxidation products by HPLC in the assessment of superoxide production and NADPH oxidase activity in vascular systems.
pubmed:affiliation
Vascular Biology Laboratory, Heart Institute (InCor), University of São Paulo School of Medicine, Av. Eneas Carvalho Aguiar, 44 CEP, 05403-000 São Paulo, Brazil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't