US EPA

1498939 

Technical Report 

The Role of Macrophages as a Source of Reactive Oxygen Intermediates in Pulmonary Inflammation Associated with Pathogenic Dusts 

Donaldson, K; Slight, J; Brown, GM; Bolton, RE; Davis, JMG 

1986 

HASKELL LAB 

NIOSH/00172181 

Edinburgh 

TM/86/09 Colt Foundation Contract CF/07/84 

A study was performed to characterize the role of macrophages in the release of reactive oxygen intermediates (ROI) in the lungs of rats inflamed by mineral dusts. The study was divided into three parts: the effect of mineral dusts on ROI production by alveolar leukocytes in-vitro, an examination of the ability of ROI to damage epithelial cells, and an examination of the effect of culture on collagen gel on the alveolar macrophage production of ROI. Bronchoalveolar leukocyte cells were obtained by lavage from SPF inbred PVG-rats 16 hours after Corynebacterium-parvum injection, 5 days after quartz (14808607) injection intratracheally (1 milligram in 0.5 milliliter suspension), and from untreated rats. The results showed that neither inert titanium-dioxide (13463677) dust nor the toxic dusts, quartz and chrysotile asbestos (12001295), provoked the release of ROI when added to the cells in-vitro. Inflammatory leukocytes released proteases and ROI which caused detachment of epithelial cells in coculture. Cells grown on a collagen gel released less ROI than those grown on a plastic surface. The authors conclude that the accumulation of ROI in lungs inflamed by mineral dusts is not the direct result of dust triggering the cells, and that the lung collagen does not contribute to the increased formation of ROI. 

DCN-160986; In vitro studies; Immune reaction; Lung irritants; Lung cells; Laboratory animals; Silica dusts; Mineral dusts; Physiological response; Quartz dust