laminaran and Alveolitis--Extrinsic-Allergic

To test the hypothesis that airborne microbial cell wall components could induce an inflammatory response in the lungs, measurements were made of the amounts of bacterial endotoxin and (1-->3)-beta-D-glucan in laboratory animal bedding materials. Groups of rats were exposed by inhalation to airborne endotoxin, (1-->3)-beta-D-glucan or a combination of the two for 5 weeks. The results demonstrated that measurable amounts of endotoxin and (1-->3)-beta-D-glucan could be detected in the different bedding materials. In contrast to animals at delivery, those kept on bedding for 5 weeks showed moderate inflammatory reactions in the lung. These were most pronounced among animals exposed to endotoxin and (1-->3)-beta-D-glucan. The results suggest that further studies need to be undertaken to elucidate the role of microbial cell wall products in the development of inflammatory lung responses among research animals.

Topics: Administration, Inhalation; Aerosols; Air Pollutants; Alveolitis, Extrinsic Allergic; Animals; Bedding and Linens; beta-Glucans; Bronchoalveolar Lavage Fluid; Dose-Response Relationship, Immunologic; Equipment Contamination; Escherichia coli; Female; Glucans; Lipopolysaccharides; Lung; Rats; Rats, Sprague-Dawley

In an animal model of hypersensitivity pneumonitis (HP) guinea-pigs were exposed for 5 weeks to an aerosol of bacterial endotoxin, beta(1,3)-D-glucan (curdlan) or a combination. Exposure to endotoxin or curdlan showed only small changes in inflammatory cells in airways or the lung wall, histologically or in terms of enzyme secretion from alveolar macrophages. When the two agents were given together, a histology resembling HP was seen with alveolar infiltrates and early granulomas. Inflammatory cells in airways were increased and enzyme production of macrophages was changed, suggesting an effect of curdlan on the inflammatory regulating capacity of airway macrophages. The results suggest that interference with macrophage function and inflammation are important components in the development of HP.

Topics: Acetylglucosaminidase; Alveolitis, Extrinsic Allergic; Animals; beta-Glucans; Bronchoalveolar Lavage Fluid; Cathepsin D; Endotoxins; Female; Glucans; Guinea Pigs; Lung; Macrophages, Alveolar

Samples of bird droppings were collected and the amount of endotoxin and (1-->3)-beta-D-glucan in these was determined using a specific Limulus assay. All samples contained these agents and calculations on airborne levels demonstrated that doses at risk for inflammation and allergic alveolitis were present. Endotoxin and (1-->3)-beta-D-glucan should be considered in investigations on lung disease induced by bird droppings.

Topics: Alveolitis, Extrinsic Allergic; Animals; beta-Glucans; Birds; Dust; Endotoxins; Feces; Glucans; Limulus Test