Abstract |
Knowledge of ozone (O3) uptake in rats is integral to efforts to quantitatively extrapolate animal data to man. The authors have measured percent uptake 30 adult Sprague Dawley rats exposed, nose only, for 1 hr to 0.3, 0.6 or 1.0 ppm O3. Resting breathing measurements were obtained by plethysmography while changes in ozone, oxygen, and carbon dioxide, due to animal breathing, were computed. Ozone uptake was calculated by a fractional deposition technique, i.e. O3 in vs. O3 out. Pulmonary O3 uptake was found to be approximately 40 percent of that inspired. The value did not vary over time nor was it affected by O3 concentration. Although ozone uptake did not appear to be influenced by ventilatory changes within normal breathing limits, it was positively correlated with respiratory gas exchange. The quantitative retention of O3 by the respiratory epithelium increased proportionally with O3 concentration and minute volume. (Copyright (c) 1987 Academic Press, Inc.) |