Français
Albanian
Arabic
Armenian
Azerbaijani
Belarusian
Bengali
Bosnian
Catalan
Czech
Danish
Deutsch
Dutch
English
Estonian
Finnish
Français
Greek
Haitian Creole
Hebrew
Hindi
Hungarian
Icelandic
Indonesian
Irish
Italian
Japanese
Korean
Latvian
Lithuanian
Macedonian
Mongolian
Norwegian
Persian
Polish
Portuguese
Romanian
Russian
Serbian
Slovak
Slovenian
Spanish
Swahili
Swedish
Turkish
Ukrainian
Vietnamese
Български
中文(简体)
中文(繁體)
Archives of Biochemistry and Biophysics 1992-May

Responses of vascular endothelial oxidant metabolism to lipopolysaccharide and tumor necrosis factor-alpha.

Seuls les utilisateurs enregistrés peuvent traduire des articles
Se connecter S'inscrire
Le lien est enregistré dans le presse-papiers
J A Royall
P D Gwin
D A Parks
B A Freeman

Mots clés

Abstrait

Quantification of intracellular and extracellular levels and production rates of reactive oxygen species is crucial to understanding their contribution to tissue pathophysiology. We measured basal rates of oxidant production and the activity of xanthine oxidase, proposed to be a key source of O2- and H2O2, in endothelial cells. Then we examined the influence of tumor necrosis factor-alpha and lipopolysaccharide on endothelial cell oxidant metabolism, in response to the proposal that these inflammatory mediators initiate vascular injury in part by stimulating endothelial xanthine oxidase-mediated production of O2- and H2O2. We determined a basal intracellular H2O2 concentration of 32.8 +/- 10.7 pM in cultured bovine aortic endothelial cells by kinetic analysis of aminotriazole-mediated inactivation of endogenous catalase. Catalase activity was 5.72 +/- 1.61 U/mg cell protein and glutathione peroxidase activity was much lower, 8.13 +/- 3.79 mU/mg protein. Only 0.48 +/- 0.18% of total glucose metabolism occurred via the pentose phosphate pathway. The rate of extracellular H2O2 release was 75 +/- 12 pmol.min-1.mg cell protein-1. Intracellular xanthine dehydrogenase/oxidase activity determined by pterin oxidation was 2.32 +/- 0.75 microU/mg with 47.1 +/- 11.7% in the oxidase form. Intracellular purine levels of 1.19 +/- 1.04 nmol hypoxanthine/mg protein, 0.13 +/- 0.17 nmol xanthine/mg protein, and undetectable uric acid were consistent with a low activity of xanthine dehydrogenase/oxidase. Exposure of endothelial cells to 1000 U/ml tumor necrosis factor (TNF) or 1 microgram/ml lipopolysaccharide (LPS) for 1-12 h did not alter basal endothelial cell oxidant production or xanthine dehydrogenase/oxidase activity. These results do not support a casual role for H2O2 in the direct endothelial toxicity of TNF and LPS.

Rejoignez notre
page facebook

La base de données d'herbes médicinales la plus complète soutenue par la science

  • Fonctionne en 55 langues
  • Cures à base de plantes soutenues par la science
  • Reconnaissance des herbes par image
  • Carte GPS interactive - étiquetez les herbes sur place (à venir)
  • Lisez les publications scientifiques liées à votre recherche
  • Rechercher les herbes médicinales par leurs effets
  • Organisez vos intérêts et restez à jour avec les nouvelles recherches, essais cliniques et brevets

Tapez un symptôme ou une maladie et lisez des informations sur les herbes qui pourraient aider, tapez une herbe et voyez les maladies et symptômes contre lesquels elle est utilisée.
* Toutes les informations sont basées sur des recherches scientifiques publiées

Google Play badgeApp Store badge