Pharmacology of vagal afferent nerve activity in guinea pig airways.

The excitability and activity of vagal afferent nerves innervating the airways can be pharmacologically increased and decreased. Autacoids released as a result of airway inflammation can lead to substantial increases in afferent nerve activity, consequently altering pulmonary reflex physiology. In a manner analogous to hyperalgesia associated with inflammation in the somato-sensory system, increases in vagal afferent nerve activity in inflamed airways may lead to a heightened cough reflex, and increases in autonomic activity in the airways. These effects may contribute to many of the symptoms of inflammatory airway disease. Here we provide a brief overview of some of the mechanisms by which the afferent activity in airway nerves can be pharmacologically modified.