Linked Life Data

16540392

Source:http://linkedlifedata.com/resource/pubmed/id/16540392

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2006-3-16
pubmed:abstractText
The oxidation of 2',7'-dichlorofluorescin (DCFH) and its diacetate form (DCFHDA) by the HRP/peroxynitrite system was investigated. Both DCFH and DCFHDA were oxidized to fluorescent products. A major anomaly, however, was the observation that fluorescence continued to build up long after peroxynitrite total decomposition and the initial HRP compound I reduction, suggesting the production of oxidants by the system. Indeed, preformed HRP compound I was instantly reduced by DCFH and DCFHDA to compound II with the obligate formation of DCF(-) semiquinone and DCFHDA-derived radicals. Catalase strongly inhibited fluorescence and EPR signals, suggesting the intermediate formation of H2O2. Taken together the data indicate that peroxynitrite rapidly oxidizes HRP to HRP compound I, which is reduced by DCFH and its diacetate form with the concomitant formation of DCF(-) semiquinone and DCFHDA-derived radicals. These are oxidized by O2, producing O2(-) (as demonstrated by EPR and oxygen consumption experiments), which dismutates to produce H2O2, which serves to fuel further DCFH/DCFHDA oxidation via HRP catalysis. Also DCFHDA was shown to be considerably more resistant to oxidation than its hydrolyzed product DCFH, presumably because of the absence of the easily oxidizable phenol moieties. DCFHDA/DCFH have been used to study free radical production in a variety of systems. Our findings demonstrate that this assay is subject to a serious artifact in that it produces what it is purported to measure; therefore, its use in biological systems should be approached with caution.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0891-5849
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
968-75
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
The oxidation of 2',7'-dichlorofluorescin to reactive oxygen species: a self-fulfilling prophesy?
pubmed:affiliation
Laboratory of Pharmacology and Chemistry, Ntional Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA. bonini@niehs.nih.gov
pubmed:publicationType
Journal Article, Research Support, N.I.H., Intramural