Linked Life Data

10415107

Source:http://linkedlifedata.com/resource/pubmed/id/10415107

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1999-9-8
pubmed:abstractText
Peroxynitrite, the reactive species formed in vivo by the reaction of nitric oxide with superoxide anion, is capable of diffusing across erythrocyte membranes via anion channels and passive diffusion (A. Denicola, J. M. Souza, and R. Radi, Proc. Natl. Acad. Sci. USA 95, 3566-3571, 1998). However, peroxynitrite diffusion could be limited by extracellular targets, with the reaction with CO(2) (k(2) = 4.6 x 10(4) at 37 degrees C and pH 7.4) the most relevant. Herein, we studied the influence of physiological concentrations of CO(2) on peroxynitrite diffusion across intact red blood cells. The presence of CO(2) inhibited the oxidation of intracellular oxyhemoglobin by externally added peroxynitrite. However, the inhibition by CO(2) decreased at increasing red blood cell densities. At 45% hematocrit, 1.3 mM CO(2) (in equilibrium with 24 mM bicarbonate, at pH 7.4 and 25 degrees C) only inhibited 30% of intracellular oxyhemoglobin oxidation. This partial inhibition was also observed in red blood cells pretreated with the anion exchanger inhibitor 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid, ruling out a competition between peroxynitrite and bicarbonate for the transport through the anion channel. A theoretical model was developed to estimate the diffusion distance and half-life of extracellular peroxynitrite before reacting with intracellular oxyhemoglobin, at different red blood cell densities, and in the presence or absence of CO(2). The theoretical model correlated well with the experimental data. Our results indicate that, even in the presence of CO(2), peroxynitrite is able to diffuse and reach the inside of the erythrocyte.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0003-9861
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Academic Press.
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
368
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
23-30
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Diffusion of peroxynitrite in the presence of carbon dioxide.
pubmed:affiliation
Facultad de Ciencias, Department of Physical Biochemistry, Universidad de la Rupública, Montevideo, Uruguay.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't