Bronchial and alveolar allergen-induced anaphylaxis and the stimulation of bronchial mucociliary clearance in ragweed-sensitized dogs.

In allergic airways disease, we hypothesized that an acute allergen inhalation activates cells in the bronchial and alveolar regions of the lungs to initiate cardiopulmonary anaphylactic responses that include the stimulation of bronchial mucociliary clearance. Seven beagles were neonatally sensitized to ragweed allergen, and four were sham-sensitized. Adult dogs were anesthetized with propofol and etomidate. Bronchial retention of radiotagged particles deposited in the lungs was monitored with a gamma camera. Then 0.4-1.8 micrograms of ragweed allergen was deposited either proximally or peripherally in the lungs while achieving a similar total mass deposited. Both proximal and peripheral allergen deposition elicited cardiopulmonary responses characteristic of anaphylaxis. Following proximal allergen deposition, the mean bronchial mucuciliary clearance at 60 min increased from 27.5% +/- 4.9% to 59.9% +/- 3.3% (p < .01), and following peripheral deposition it increased from 5.9% +/- 3.1% to 52.9% +/- 7.2% (p < .01). No allergen-induced suppression of bronchial mucociliary clearance was detected within the 140-min postexposure period. No changes in cardiopulmonary responses or bronchial mucociliary clearance in the unsensitized dogs could be ascribed to the inhalation of allergen. Both the bronchi and alveoli are target sites for the initiation of allergen-induced respiratory and cardiovascular anaphylactic responses and the stimulation of bronchial mucociliary clearance.