Histamine receptors in the human nose.

The aim of this study was to determine the role of histamine receptors in the nose. The effects of intranasal histamine challenge were compared with those of a specific H1-receptor agonist, betahistine and a specific H2-receptor agonist, impromidine, in 11 normal individuals and four with rhinitis. Sneezing, nasal irritation and hypersecretion were induced by histamine and the H1-receptor agonist, betahistine only. Nasal airway resistance (Rna) was measured by passive anterior rhinomanometry. Histamine, betahistine and impromidine all induced rises in Rna in both normal individuals and those with rhinitis but histamine had the most potent effect; the H2-receptor effect on Rna was predominant over that of the H1-receptor. The sensitivity to all three agonists was greater in the individuals with rhinitis.