Pharmacological regulation of the neuronal control of airway mucus secretion.

The dominant neural control of human airway mucus secretion is cholinergic. There is no adrenergic control and sensory-efferent control is equivocal. Recent advances have identified several mechanisms that inhibit neurogenic mucus secretion. Muscarinic M3 receptor antagonists and tachykinin NK1 receptor antagonists inhibit neurogenic secretion. Muscarinic M2 receptors, nitric oxide and vasoactive intestinal peptide are inhibitory and regulate the magnitude of neurogenic secretion. The opening of large-conductance calcium-activated potassium channels is a common endogenous inhibitory mechanism and may represent the best therapeutic target. None of these inhibitory options are currently being targeted specifically for therapy of airway hypersecretion.