Functional Disturbances of the Autonomic Nerve in Nasal Hyperreactivity: An Up-date Review

Abstract

During the 1980s, our view of airway hypersensitivity was altered significantly. Advances in biochemical techniques revealed involvement of several nonspecific events in nasal hyperreactivity: Autonomic dysfunction involving primary and/or secondary receptor disorders, epithelial damage by cytotoxic proteins in eosinophil, which is stimulated by inflammatory mediators, and an axonal reflex of sensory C fibers. Since 1983, we have neurobiochemically investigated the autonomic nerve dysfunction in the nasal mucosa of patients with nasal allergy and guinea pigs with experimentally-induced nasal hypersensitivity. We propose the following mechanisms as potential contributors to the disturbance of the beta receptor function in airway hyperreactivity: i) Down-regulation caused by excess endogenous norepinephrine stimulation, ii) down-regulation and uncoupling to adenylate cyclase, produced by the inflammatory mediator-induced activation of protein kinase C, iii) the action of beta receptor inhibitory factor, presumably anti beta receptor autoantibodies, and iv) dysfunction of beta receptor kinase, which is known to cause short-term desensitization of beta receptors after exposure to beta agonists. This review provides the anatomical and neurobiochemical background for the autonomic regulation and dysfunction in the nose. We also introduce our series of experiments and the above updated hypotheses of how functional disturbances of the autonomic nerve in the nasal mucosa may occur.