Demonstration of inflammatory cell population changes in rat lungs in response to intratracheal instillation of spring wheat dust using lung enzymatic digestion and centrifugal elutriation.
Keller-GE III; Lewis-DM; Olenchock-SA
Comp Immunol Microbiol Infect Dis 1987 Jan; 10(3-4):219-226
The response of inflammatory cells in the lung and peripheral blood was determined during short term time course exposures to inhaled grain dust in specific pathogen free Lewis-rats. Grain dust suspensions were prepared from airborne spring wheat dust collected from port grain terminals in the Superior-Duluth region; dust was suspended in saline at 4 milligrams per millimeter (mg/ml). Spring wheat dust suspension or saline (control) was instilled in rats intratracheally; 6 or 24 hours later, rats were killed. Alveolar macrophages were collected by bronchoalveolar lavage. Significant increases were noted in neutrophils at both the 6 and 24 hour time periods in animals receiving the dust. Lymphocyte numbers were significantly higher in the control group than in the dust treated group. Significantly elevated numbers of granulocytes were present in the dust exposed lung and airways surfaces as determined by bronchoalveolar lavage. On examination of enzymatic digestion of rat lungs a significantly higher number of neutrophils was found in the dust exposed animals at both 6 and 24 hours than was seen for the controls. A large increase in the number of neutrophils in the alveoli was found on histological examination of the dust treated animals at 6 hours. No specific precipitating antibodies were noted on counterimmunoelectrophoresis of random serum samples from control and exposed rats. The data were consistent with a time course for an inflammatory process subsequent to the instillation of spring wheat dust. The authors conclude that intratracheal instillation of airborne grain dust resulted in inflammatory cell activation. The neutrophil was the primary responding cell with increases noted in neutrophils in the peripheral blood, bronchoalveolar spaces, and lung interstitium.
NIOSH-Author; Laboratory-animals; Plant-dusts; Lung-cells; Blood-cells; Airborne-dusts; Dust-inhalation; Grain-dusts; In-vivo-studies;
Author Keywords: Inflammation; spring wheat dust; lung; rats; neutrophils; enzymatic digestion; centrifugal elutriation; occupational health; agriculture
Comparative Immunology, Microbiology and Infectious Diseases