The localization of DMPO spin adducts of OH in endothelial cells exposed to hydrogen peroxide.
Toxicol Lett
; 81(1): 73-8, 1995 Nov.
Article
em En
| MEDLINE
| ID: mdl-8525501
ABSTRACT
Examination by electron spin resonance (ESR) spectroscopy revealed the localization of 5,5-dimethyl-l-pyrroline-N-oxide (DMPO) spin adducts of hydroxyl radicals (.OH) produced by bovine endothelial cells exposed to hydrogen peroxide. Addition of 10 mM chromium oxalate, a line-broadening agent, to the reaction mixture virtually abolished the signal of DMPO-OH spin adducts. Moreover, the spin adducts were recovered in the filtrated fraction of the cell suspension. We, therefore, concluded that the location of DMPO-OH due to .OH radicals produced by endothelial cells was extracellular. Contrastingly, the site of formation of DMPO-OH was confirmed to be intracellular by the effect of Desferal, an iron chelator, and the effect of poly(ethylene glycol), an extracellular scavenger of OH radicals, as previously reported. The DMPO-OH adducts in the cell suspension mixture were degraded by a cyanide sensitive pathway and they were apparently more unstable than in the extracellular fraction. The initial amount of DMPO-OH adducts formed in endothelial cells could potentially be monitored by the DMPO-OH signals in the extracellular reaction mixture better than those in the cell suspension mixture.
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Base de dados:
MEDLINE
Assunto principal:
Endotélio Vascular
/
Sequestradores de Radicais Livres
/
Oxidantes
/
Óxidos N-Cíclicos
/
Peróxido de Hidrogênio
Limite:
Animals
Idioma:
En
Revista:
Toxicol Lett
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Japão