Adventitia-derived nitric oxide in rat aortas exposed to endotoxin: cell origin and functional consequences
1 Pharmacologie et Physico-Chimie des Interactions Cellulaires et Moléculaires, Unité Mixte de Recherche 7034, and 2 Institut de Physiologie et Chimie Biologique, Unité Mixte de Recherche 7519, Centre National de la Recherche Scientifique, Université Louis Pasteur de Strasbourg, 67401 Illkirch, Fr...
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Published in | American journal of physiology. Heart and circulatory physiology Vol. 279; no. 6; pp. H2743 - H2751 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
United States
01.12.2000
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Subjects | |
Online Access | Get full text |
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Summary: | 1 Pharmacologie et Physico-Chimie des Interactions
Cellulaires et Moléculaires, Unité Mixte de Recherche 7034, and 2 Institut de Physiologie et Chimie Biologique, Unité
Mixte de Recherche 7519, Centre National de la Recherche Scientifique,
Université Louis Pasteur de Strasbourg, 67401 Illkirch,
France
The role of
adventitial cells in bacterial lipopolysaccharide (LPS)-induced
vascular nitric oxide (NO) overproduction has been largely ignored. In
rat aortas exposed to LPS in vitro or in vivo, it was found that
adventitia contained the major part of NO synthase (NOS)-2 protein
(Western blot and immunohistochemistry) and generated the largest
amount of NO (electron paramagnetic resonance spin trapping). NOS-2
immunoreactive cells were mainly resident macrophages at an early stage
(5 h, in vitro or in vivo) and fibroblasts at a later stage (20 h, in
vitro). Adventitial NOS-2 activity largely accounted for 1 )
the relaxing effect of L -arginine in rings exposed to LPS
in vivo, 2 ) generation of an "NO store" revealed by
N -acetylcysteine-induced relaxation, and 3 )
formation of protein-bound dinitrosyl iron complexes in the medial
layer of aortic rings exposed to LPS in vitro. In conclusion, the
adventitia is a powerful source of NO triggered by LPS in the rat
aorta. This novel source of NO has an important impact on smooth muscle
function and might be implicated in various inflammatory diseases.
adventitial fibroblasts; adventitial macrophages; dinitrosyl iron
complexes; electron paramagnetic resonance spin trapping |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0363-6135 1522-1539 |
DOI: | 10.1152/ajpheart.2000.279.6.h2743 |