Abstract |
Surfactant protein D ( SP-D) (CP4) is a collagenous surfactant-associated carbohydrate binding protein that is synthesized and secreted by alveolar epithelial cells. Previous studies have shown that intratracheal administration of crystalline silica to rats elicits a marked increase in the alveolar accumulation of surfactant lipids and surfactant protein A (SP-A). The authors examined the accumulation of SP-D using this animal model of alveolar proteinosis. Immunoperoxidase localization of SP-D studies at 2 weeks after silica instillation showed intense staining of intra-alveolar exudates, and cytoplasmic staining of hypertrophic type II cells. Immunoelectron microscopy showed that airspace SP-D was specifically associated with granular material, but not tubular myelin or other membranous structures. SP-D was quantified in bronchoalveolar lavage by immunoassay using antibodies specific for SP-D, and by reversephase HPLC after affinity purification of SP-D on maltosyl- agarose. Within 2 weeks after silica instillation, there was a greater than 45-fold increase in lavage SP-D per lung compared with saline controls, including an almost ten-fold increase in the insoluble or surfactant-associated protein. These studies indicate that the extracellular accumulation of SP-D is markedly increased in silica-induced lipoproteinosis, and that SP-D is associated with amorphous components identified by electron microscopy.
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Authors | E Crouch, A Persson, D Chang, D Parghi |
Journal | The American journal of pathology
(Am J Pathol)
Vol. 139
Issue 4
Pg. 765-76
(Oct 1991)
ISSN: 0002-9440 [Print] United States |
PMID | 1656758
(Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Antibodies
- Glycoproteins
- Pulmonary Surfactant-Associated Protein D
- Pulmonary Surfactants
- Silicon Dioxide
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Topics |
- Animals
- Antibodies
(immunology)
- Bronchoalveolar Lavage Fluid
(chemistry)
- Chromatography, High Pressure Liquid
- Epithelium
(metabolism, ultrastructure)
- Glycoproteins
(analysis, immunology, metabolism)
- Immunoenzyme Techniques
- Lipoid Proteinosis of Urbach and Wiethe
(chemically induced, metabolism)
- Lung Diseases
(chemically induced, metabolism)
- Microscopy, Electron
- Microscopy, Immunoelectron
- Pulmonary Alveoli
(metabolism, ultrastructure)
- Pulmonary Surfactant-Associated Protein D
- Pulmonary Surfactants
(analysis, immunology, metabolism)
- Rats
- Rats, Inbred Strains
- Silicon Dioxide
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