The effect of nasal and nasopharyngeal irritation on airway resistance in man.

Abstract

Ten subjects ranging in age from 21 to 60 years with no history of bronchopulmonary disease had the mucosa of the nasal and nasopharyngeal area exposed to silica particles for 150 seconds. Significant increases in airway resistance, as measured by body plethysmography, were noted in all 10 subjects. Prior injection of atropine in pharmacologic dose prevented increase of resistance after a similar silica exposure. The results suggest that stimulation of receptor sites confined to the nose and nasopharynx can initiate an increase in tracheobronchial airway resistance. The most likely mechanism is neural via reflex pathways. Because most irritant particles are trapped in the nose, the studies also suggest that bronchospasm and resistance changes can be initiated by reflexes originating in the nose.