Comparisons of breathing rate, cellular response, airway obstruction (determined by postmortem pulmonary hyperinflation) and the wet/dry weight ratios of guinea pigs exposed to cotton dust aerosol.
Frazer-DG; Robinson-VA; DeLong-DS; Castranova-V; Jones-TA; Petsonk-EL
Cotton dust: proceedings of the Thirteenth Cotton Dust Research Conference, beltwide cotton research conferences, January 5-6, 1989, Nashville, Tennessee. Jacobs RR, Wakelyn PJ, eds. Memphis, TN; The National Cotton Council of America, 1989 Apr; :129-133
Guinea-pigs were exposed to a cotton dust aerosol and their breathing rate in air and 10 percent carbon-dioxide in air was determined. Lung cellular response was measured by pulmonary lavage. The amount of airway obstruction was estimated by determining alterations in postmortem pulmonary hyperinflation and the changes in the wet/dry weight ratio were used as an index of lung fluid balance. The objective of this investigation was to determine the temporal relationships between these pulmonary responses following acute exposure to cotton dust, so that the interaction between the lung cellular response and airway obstruction resulting from exposure to cotton dust could be better understood. Four different pulmonary responses of the control and cotton dust exposed animals were measured prior to exposure, at 0 hours post exposure, and at 18 hours after exposure. Breathing rate was measured in air and in 10 percent carbon-dioxide in air for all animals in each group. Leukocyte and macrophage recovery was determined following bronchopulmonary lavage in one half of each exposed and control group. Airway obstruction was also estimated in the remaining exposed and control animals by determining changes in the wet/dry weight of excised lungs used in the hyperinflation measurements. The results indicated that in guinea-pigs exposed to cotton dust, airway obstruction occurred prior to the maximum influx of leukocytes into the lung, indicating that leukocyte infiltration may not be responsible for airway obstruction. The breathing rate response measured in air and 10 percent carbon-dioxide appeared to be a good indicator of fluid and leukocyte infiltration into the lung, but did not appear to accurately reflect changes in airway obstruction.
Dust-inhalation; Airborne-dusts; Cotton-dust; Laboratory-animals; Pulmonary-system-disorders; Respiratory-rate; Inhalation-studies; Pulmonary-function
Cotton dust: proceedings of the Thirteenth Cotton Dust Research Conference, beltwide cotton research conferences, January 5-6, 1989, Nashville, Tennessee