Hypoxic contraction of small pulmonary arteries from normal and endotoxemic rats: fundamental role of NO.

Détails

ID Serval
serval:BIB_2256EB5B5CC1
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Hypoxic contraction of small pulmonary arteries from normal and endotoxemic rats: fundamental role of NO.
Périodique
AJP: Heart and Circulatory Physiology
Auteur(s)
Terraz S., Baechtold F., Renard D., Barsi A., Rosselet A., Gnaegi A., Liaudet L., Lazor R., Haefliger J.A., Schaad N., Perret C., Kucera P., Markert M., Feihl F.
ISSN
0363-6135
Statut éditorial
Publié
Date de publication
1999
Volume
276
Numéro
4
Pages
H1207-H1214
Langue
anglais
Notes
Publication types: In Vitro ; Journal Article
Résumé
The present study was aimed at examining the role of nitric oxide (NO) in the hypoxic contraction of isolated small pulmonary arteries (SPA) in the rat. Animals were treated with either saline (sham experiments) or Escherichia coli lipolysaccharide [LPS, to obtain expression of the inducible NO synthase (iNOS) in the lung] and killed 4 h later. SPA (300- to 600-micrometer outer diameter) were mounted as rings in organ chambers for the recording of isometric tension, precontracted with PGF2alpha, and exposed to either severe (bath PO2 8 +/- 3 mmHg) or milder (21 +/- 3 mmHg) hypoxia. In SPA from sham-treated rats, contractions elicited by severe hypoxia were completely suppressed by either endothelium removal or preincubation with an NOS inhibitor [NG-nitro-L-arginine methyl ester (L-NAME), 10(-3) M]. In SPA from LPS-treated rats, contractions elicited by severe hypoxia occurred irrespective of the presence or absence of endothelium and were largely suppressed by L-NAME. The milder hypoxia elicited no increase in vascular tone. These results indicate an essential role of NO in the hypoxic contractions of precontracted rat SPA. The endothelium independence of HPV in arteries from LPS-treated animals appears related to the extraendothelial expression of iNOS. The severe degree of hypoxia required to elicit any contraction is consistent with a mechanism of reduced NO production caused by a limited availability of O2 as a substrate for NOS.
Mots-clé
Animals, Anoxia, Endotoxemia, Lipopolysaccharides, Male, Nitric Oxide, Nitric Oxide Synthase, Nitric Oxide Synthase Type II, Pulmonary Artery, Rats, Rats, Wistar, Reference Values, Vasoconstriction
Pubmed
Web of science
Création de la notice
25/01/2008 14:48
Dernière modification de la notice
20/08/2019 13:59
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