Enhanced clearance of surfactant protein D during LPS-induced acute inflammation in rat lung.

Abstract

Pulmonary surfactant participates in the regulation of alveolar compliance and lung host defense. Surfactant homeostasis is regulated through a combination of synthesis, secretion, clearance, recycling, and degradation of surfactant components. The extracellular pool size of surfactant protein (SP) D fluctuates significantly during acute inflammation. We hypothesized that changes in SP-D levels are due, in part, to altered clearance of SP-D. Clearance pathways in rats were assessed with fluorescently labeled SP-D that was instilled into control lungs or lungs that had been treated with lipopolysaccharide (LPS) 16 h earlier. SP-D clearance from lavage into lung tissue was time dependent from 5 min to 1 h and 1.7-fold greater in LPS-treated lungs than in control lungs. Analysis of cells isolated by enzymatic digestion of lung tissue revealed differences in the SP-D-positive cell population between groups. LPS-treated lungs had 28.1-fold more SP-D-positive tissue-associated neutrophils and 193.6-fold greater SP-D association with those neutrophils compared with control lungs. These data suggest that clearance of SP-D into lung tissue is increased during inflammation and that tissue-associated neutrophils significantly contribute to this process.

• Authors: J F Herbein, J R Wright
• Journal: American journal of physiology. Lung cellular and molecular physiology (Am J Physiol Lung Cell Mol Physiol) Vol. 281 Issue 1 Pg. L268-77 (Jul 2001) ISSN: 1040-0605 [Print] United States
• PMID: 11404270 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Glycoproteins
• Lipopolysaccharides
• Proteolipids
• Pulmonary Surfactant-Associated Protein D
• Pulmonary Surfactant-Associated Proteins
• Pulmonary Surfactants
• Thyroglobulin

Topics

• Acute Disease
• Animals
• Bronchoalveolar Lavage Fluid (cytology)
• Cell Count
• Glycoproteins (antagonists & inhibitors, metabolism)
• Lipopolysaccharides (pharmacology)
• Lung (drug effects, metabolism, pathology)
• Macrophages (drug effects, metabolism)
• Male
• Neutrophils (metabolism)
• Pneumonia (chemically induced, metabolism, pathology)
• Proteolipids (metabolism)
• Pulmonary Surfactant-Associated Protein D
• Pulmonary Surfactant-Associated Proteins
• Pulmonary Surfactants (antagonists & inhibitors, metabolism)
• Rats
• Rats, Sprague-Dawley
• Thyroglobulin (metabolism)