Nasal congestion model in Brown Norway rats and the effects of some H1-antagonists.

The aim of this study was to develop and characterize a new model for evaluating nasal congestion in rats by using whole body plethysmography (WBP)-free moving application. Brown Norway rats were sensitized with 10% toluene-2, 4-diisocyanate (TDI) solution, and nasal congestion was provoked with 5% TDI. An increase in the enhanced pause (Penh) was recognized after being challenged with TDI. In addition, a significant increase in the Penh was observed following the intranasal application of histamine in TDI sensitized rats. Histamine H1 antagonists, such as chlorpheniramine and ketotifen suppressed the increase of Penh during the early-phase response. On the other hand, epinastine suppressed the increase of Penh in both the early and late phase responses. In conclusion, we developed an allergic rhinitis model that includes nasal congestion symptoms in Brown Norway rats, and this model may be useful for evaluating the effects of drugs on nasal congestion.