Effect of silica inhalation on pulmonary alveolar macrophages (PAM) and microsomal cytochrome P450 activities.
Pailes-W; Rabovsky-J; Judy-D; Tucker-J; Castranova-V; Lantz-RC
Respirable dust in the mineral industries health effects, characterization, and control: proceedings of the International Symposium on Respirable Dust in Mineral Industries. Frantz RL, Ramani RV, ed. University Park, PA: Pennsylvania State University, 1988 Jan; :169-176
The effect of silica (14808607) on pulmonary alveolar macrophages and microsomal cytochrome-P450 dependent enzyme activities was studied in rats. Male Sprague-Dawley-rats were exposed to aerosols of Min-U-Sil-10 (14808607) at concentrations of 0 or 20 micrograms per cubic meter 16 hours a day 5 days a week for 4 weeks. They were then killed and the lungs were lavaged and total cell number, cellular volume, and percentage alveolar macrophages were determined. The membrane integrity of the macrophages was assessed by the trypan-blue exclusion test. Superoxide-anion (O2(-)) release was evaluated by measuring O2(-) dependent release of cytochrome-C. Resting and zymosan stimulated chemiluminescence was measured. Monolayers of lavaged macrophages were prepared and examined by electron microscopy. The lungs of other rats were homogenized and the microsomal fraction was isolated and assayed for basal and beta- naphthoflavone induced ethoxyresorufin-deethylase and ethoxycoumarin- deethylase (ECOD) activity. Silica caused nonsignificant decreases in the number of alveolar macrophages recovered in the lavage fluid and baseline ECOD activity. Macrophages from exposed animals exhibited less spreading and less surface ruffling, many cells appearing rounded with few membrane projections. The other parameters were not significantly altered by silica exposure. The authors conclude that 4 weeks of exposure to silica does not significantly affect the cellular function of lavaged alveolar macrophages or cytochrome-P450 dependent enzyme activities.
Silica-dusts; In-vivo-studies; Laboratory-animals; Inhalation-studies; Alveolar-cells; Enzyme-complexes; Biochemical-indicators; Physiological-chemistry; Laboratory-techniques
Respirable dust in the mineral industries health effects, characterization, and control: proceedings of the International Symposium on Respirable Dust in Mineral Industries