Linked Life Data

2540065

Source:http://linkedlifedata.com/resource/pubmed/id/2540065

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1989-6-5
pubmed:abstractText
The reactions of superoxide radical with persistent nitroxide spin-adducts or with stable spin-labels were studied using ESR spectrometry. Superoxide radicals were produced enzymatically using xanthine - xanthine oxidase or chemically by dissolving potassium superoxide in DMSO. Hydroxyl and methyl spin-adducts of the spin-trap DMPO were performed by sonolysis and subsequently reacted with superoxide radical. Superoxide-induced depletion of DMPO--OH obeyed second order kinetics. Contrary to previously published mechanisms, the reaction requires neither transition metal ions nor thiols. The depleted spin-adducts could not be restored by reoxidation with ferricyanide or copper +H2O2; thus, the superoxide-mediated destruction does not result in a mere one-electron reduction product. Superoxide also depletes other DMPO spin-adducts including DMPO--CH3 and DMPO--H, but not PBN--CH3. In addition, some 5-membered ring stable nitroxides are depleted by superoxide in a pseudo-zero order reaction. In studying systems which generate O2- and OH, the superoxide-induced destruction of DMPO--OH may well lead to erroneous conclusions regarding the primary radicals produced. In particular this reaction might be operative under circumstances where elevated rates of superoxide production take place, such as during oxygen consumption "burst" in phagocytosis, degranulation, or paraquat intoxication.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0891-5849
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
141-8
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Superoxide reaction with nitroxide spin-adducts.
pubmed:affiliation
Department of Molecular Biology, School of Medicine, Hebrew University of Jerusalem, Israel.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't