Lack of local neurogenic involvement in the hyperreactivity induced by epithelium removal in guinea pig trachea

Airway epithelium removal produces tracheobronchial smooth muscle hyperreactivity to different constrictor agonists. Aside from the loss of an epithelium-derived relaxant factor, other mechanisms such as production of local axon reflex could hypothetically be involved. In the present work we investigated the effect of nerve activity inhibition or ganglionic transmission blockade in the epithelium removal-induced hyperreactivity in guinea pig trachea. Tetrodotoxin, tetracaine or hexamethonium did not modify the enhanced sensitivity of denuded tracheas to histamine, suggesting that, at least under these experimental conditions, local axon or ganglionic reflexes are not involved.