Impaired norepinephrine-mediated contraction of isolated nasal mucosa in guinea pigs with allergic rhinitis.

摘要

BACKGROUND: One of the causes of nasal obstruction associated with allergic rhinitis probably is caused by the dilatation of plexus cavernosum in nasal mucosa. In this study, the change in vascular responsiveness of nasal mucosa was investigated in the septal mucosae isolated from guinea pigs with allergic rhinitis. METHODS: An allergic rhinitis model was prepared in guinea pigs by repeated challenge with aerosolized dinitrophenylated-ovalbumin antigen. Twenty-four hours after the last antigen challenge, the changes in the isometrical tension of isolated nasal septal mucosa were measured. RESULTS: In isolated nasal mucosal tissues, both norepinephrine (NE) and leukotriene D4 caused concentration-dependent contractile and relaxant responses, respectively. The NE-induced contractile response was significantly attenuated in nasal mucosae of the repeatedly antigen challenged guinea pigs. The mucosal relaxation induced by leukotriene D4 was slightly attenuated in this animal model of allergic rhinitis. CONCLUSION: This study shows an attenuation of NE-induced contraction of isolated nasal mucosa in the antigen-exposed guinea pigs. The impaired contractile response mediated by sympathetic alpha-adrenoceptors of nasal blood vessels might be involved in the development of nasal obstruction in allergic rhinitis.