Smooth muscle F-actin disassembly and RhoA/Rho-kinase signaling during endotoxin-induced alterations in pulmonary arterial compliance.
Publication year
2004Source
American Journal of Physiology : Lung Cellular and Molecular Physiology, 287, 4, (2004), pp. L649-55ISSN
Publication type
Article / Letter to editor

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Organization
Anesthesiology
Journal title
American Journal of Physiology : Lung Cellular and Molecular Physiology
Volume
vol. 287
Issue
iss. 4
Page start
p. L649
Page end
p. 55
Subject
UMCN 3.3: Neurosensory disordersAbstract
Endotoxemia is associated with changed pulmonary vascular function with respect to vasoreactivity, endothelial permeability, and activation of inducible nitric oxide synthase II (NOSII). However, whether altered passive arterial wall mechanics contribute to this endotoxin-induced pulmonary vascular dysfunction is still unknown. Therefore, we investigated whether endotoxin affects the passive arterial mechanics and compliance of isolated rat pulmonary arteries. Pulmonary arteries of pentobarbital-anesthetized Wistar rats (n = 55) were isolated and exposed to Escherichia coli endotoxin (50 microg/ml) for 20 h. Endotoxin increased pulmonary artery diameter and compliance (transmural pressure = 13 mmHg) in an endothelium-, Ca2+-, or NOSII-induced NO release-independent manner. Interestingly, the endotoxin-induced alterations in the passive arterial mechanics were accompanied by disassembly of the smooth muscle cell (SMC) F-actin cytoskeleton. Disassembly of F-actin by incubation of control arteries with the cytoskeleton-disrupting agent cytochalasin B or the Rho-kinase inhibitor Y-27632 induced a similar increase in passive arterial diameter and compliance. In contrast, RhoA activation by lysophosphatidic acid prevented the endotoxin-induced alterations in the pulmonary SMC F-actin cytoskeleton and passive mechanics. In conclusion, these findings indicate that disassembly of the SMC F-actin cytoskeleton and RhoA/Rho-kinase signaling act as mediators of endotoxin-induced changes in the pulmonary arterial mechanics. They imply the involvement of F-actin rearrangement and RhoA/Rho-kinase signaling in endotoxemia-induced vascular lung injury.
This item appears in the following Collection(s)
- Academic publications [202799]
- Faculty of Medical Sciences [80020]
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