The role of chemical mediators and mucosal hyperreactivity in nasal hypersecretion in nasal allergy.
This study was designed to elucidate, first, the degree of participation of direct effects of histamine on the nasal glands and the nasal vasculature in clinical manifestation of hyperrhinorrhea in nasal allergy and, second, the existence of hyperreactivity of the nasal glands to acetylcholine in nasal allergy. The study demonstrates that histamine released by degranulation of basophilic cells in the nasal mucosa causes nasal hypersecretion mostly by way of the reflexive pathway. Approximately 4% of the amount of nasal secretion induced by an antigen challenge in subjects with house-dust nasal allergy was due to a leakage of plasma. There were almost no direct effects of histamine on the nasal glands. Nasal secretion induced by nasal challenge with acetylcholine after vidian neurectomy comes from the nasal glands by its direct effects on the nasal glands, the amount of which indicates degree of reactivity of the nasal glands to acetylcholine independent of hypersensitivity of the mucosal sensory system. The nasal glands of vidian neurectomized subjects having nasal allergy reacted more excessively to extrinsic acetylcholine than nasal glands of subjects of the control group. This verifies the existence of hyperreactivity in the nasal glands to acetylcholine in nasal allergy. The nasal glands of nasal allergy patients may respond more excessively to a given amount of acetylcholine released from parasympathetic terminals.