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LPS inhibits endothelin-1-mediated eNOS translocation to the cell membrane in sinusoidal endothelial cells.
- Source :
-
Microcirculation (New York, N.Y. : 1994) [Microcirculation] 2005 Jul-Aug; Vol. 12 (5), pp. 433-42. - Publication Year :
- 2005
-
Abstract
- Objective: The objectives of this study were to develop a model for studying endothelin-1-mediated eNOS regulation in cultured sinusoidal endothelial cells and determine the effect of endothelin-1 and endotoxin (LPS) on eNOS localization.<br />Methods: Changes in caveolin-1, calmodulin, and eNOS expression were determined by western blot and densitometric analysis. Endothelin receptor expression and localization and the intracellular localization of eNOS and caveolin-1 were assessed by confocal microscopy.<br />Results: Sinusoidal endothelial cells expressed caveolin-1 and calmodulin, and expression was altered in cultured and passaged cells. eNOS expression decreased significantly in 24-h cultured cells, with expression dropping below the level of detection in passaged cells. Both endothelin A and endothelin B receptors were expressed on the cell surface after 24 h in culture. In 24-h cultured cells, caveolin-1 was localized in the perinuclear region and cell membrane, while eNOS was predominantly localized in the perinuclear region, where it co-localized with caveolin-1. Endothelin-1 stimulated eNOS translocation to the cell membrane. Pretreatment with LPS markedly inhibited the endothelin-1-mediated eNOS translocation.<br />Conclusions: These studies demonstrate an LPS-mediated uncoupling of endothelin receptor activation and eNOS translocation. This functional uncoupling may, in part, account for the hyperconstrictive effects of endothelin-1 during inflammatory conditions.
- Subjects :
- Animals
Cell Membrane metabolism
Cells, Cultured
Endothelial Cells drug effects
Endothelial Cells metabolism
Endothelin-1 physiology
Inflammation
Liver Circulation
Male
Nitric Oxide Synthase analysis
Nitric Oxide Synthase Type III
Protein Transport drug effects
Rats
Rats, Sprague-Dawley
Vasoconstriction
Endothelin-1 metabolism
Endothelium, Vascular cytology
Lipopolysaccharides pharmacology
Nitric Oxide Synthase metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1073-9688
- Volume :
- 12
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Microcirculation (New York, N.Y. : 1994)
- Publication Type :
- Academic Journal
- Accession number :
- 16020391
- Full Text :
- https://doi.org/10.1080/10739680590960377