BIOCHEMICAL DEFENSE MECHANISMS AGAINST PULMONARY IRRITANTS
Final rept. 15 Jul 1966-15 Jul 1967
FOOD AND DRUG RESEARCH LABS INC WAVERLY NY
Pagination or Media Count:
Studies were performed in which mammalian mucociliary apparatus has been characterized under normal conditions following exposure to three irritant gases, i.e., 100 per cent oxygen, ozoneO2 and nitrogen dioxide NO2. Investigations were made in normal and treated animals providing physical, electrophysiological, biochemical, and morphologic data of effects due to exposure. A method for in vitro microscopic observation of viable cilia and adjacent mucus blanket has been described in terms of ciliary beat and movement of particles embedded in the mucus. In vitro volumetric estimation of mucus thickness was compared to electrical resistance measurements in the attempt to provide an in vivo method to determine mucus depth alterations in treated animals. Polarographic studies of oxygen dependent enzymes were carried out on pooled stripped epithelial tissue of untreated animals and comparison made with tissues exposed to ozone and nitrogen dioxide. Exposure to 100 per cent oxygen caused a significant but selflimiting decrease in mucus velocity and viscosity. Acute exposure to nitrogen dioxide 35 and 75 micrograms per kilogram caused marked dose dependent changes in velocity and viscosity. Exposure to 0.5 ppm ozone for a 14 day period resulted in general mucostasis and elevated viscosity levels.
- Anatomy and Physiology