Participation of histamine H3 receptors in experimental allergic rhinitis of mice.

The present study was performed to study the participation of histamine H(3) receptors in nasal symptoms using Sch 50971, a potent and selective agonist of the H(3) receptor. Repeated topical application of antigen caused an increase in sneezing and nasal rubbing in sensitized mice. Oral administration of Sch 50971 and imetit, specific H(3)-receptor agonists, resulted in an inhibition of nasal symptoms induced by an antigen similar to an H(1)-receptor antagonist, cetirizine.

Substance P is involved in the effect of histamine H3 receptor agonist, Sch 50971 on nasal allergic symptoms in mice.

The aim of this study was to clarify the mechanisms of the inhibitory effect of a histamine H3 receptor agonist, Sch 50971, on nasal signs in an allergic rhinitis model in mice. The severity of allergic rhinitis was assessed by determining the extent of two markers of allergic symptoms (sneezing and nasal rubbing). The topical application of a histamine H3 receptor antagonist, clobenpropit, into the nasal cavities resulted in a dose-dependent increase in sneezing and nasal rubbing, and both Sch 50971 and a tachykinin NK1 receptor antagonist, L-733,060, inhibited these reactions in non-sensitized mice.

Effect of Usuhiratake (Pleurotus pulmonarius) on sneezing and nasal rubbing in BALB/c mice.

The anti-rhinitis properties of Pleurotus pulmonarius were investigated in BALB/c mice. A single administration of Pleurotus Pulmonarius caused no significant effect on antigen-induced nasal rubbing and sneezing at a dose of 500 mg/kg, but a significant inhibition was observed after 2 weeks of repeated treatment at this dose, and at a dose of 200 mg/kg, it also caused a significant inhibition after repeated administration for 4 weeks. Pleurotus pulmonarius showed no significant inhibitory effect on the production of IgE.