Linked Life Data

9018468

Source:http://linkedlifedata.com/resource/pubmed/id/9018468

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-6-5
pubmed:abstractText
Nitronyl nitroxides (NN), a class of compounds which react with nitric oxide forming imino nitroxides, were applied in different systems for the detection of nitric oxide. Addition of a NN to planar monolayers of bovine aortic endothelial cells (BAEC) activated by Ca2+ ionophore A23187 immediately resulted in a strong decrease of the ozone-mediated .NO chemiluminescence. Simultaneously, a rapid diminution of the electron spin resonance (ESR) signal intensity of the NN (without detectable formation of the corresponding imino nitroxide) was observed; superoxide dismutase partially inhibited this decrease in the NN concentration. Model experiments using hypoxanthine/xanthine oxidase in aqueous solution and KO2 in dimethylsulfoxide as sources of O2.- revealed that there is a rapid reduction of nitronyl nitroxides by superoxide. The second order rate constant for the reaction of the water soluble NN with O2.- was determined to be 8.8 x 10(5) M-1s-1, which is more than two orders of magnitude higher than the value reported previously for reaction with .NO (Woldman et al., BBRC 202, 195-203, 1994). Reduction of the nitronyl nitroxide was also observed in the presence of glutathione, ascorbic acid or rabbit liver microsomes. Incorporation of both nitronyl and imino nitroxides into liposomes strongly decreased reduction by superoxide and other reductants, however, in the presence of microsomes, there was no protective effect by liposomal encapsulation of NN. The results indicate that in biological systems (in addition to other reducing agents) the presence of superoxide can prevent the detection of nitric oxide using nitronyl nitroxides.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1071-5762
pubmed:author
pubmed:issnType
Print
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7-17
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Superoxide-mediated reduction of the nitroxide group can prevent detection of nitric oxide by nitronyl nitroxides.
pubmed:affiliation
Institute of Molecular Pharmacology, Berlin, Germany. HASELOFF@FMP.FTA.BERLIN.DE
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't