Role of respiratory epithelium in the development of hyperreactivity of bronchial smooth muscles.

In guinea pigs sensitized with ovalbumin the respiratory epithelium lost its ability to modulate the responses of airway smooth muscles to histaminergic stimuli. Incubation of bronchial segments with IL-5 potentiated the contractile responses of bronchial smooth muscles to histamine in both intact and sensitized animals. Incubation of bronchial segments with IL-5 receptors moderated contractile activity of segments from sensitized pigs, but not in the segments from intact controls.