The effect of a newly synthesized compound,
HSR-609, on rat experimental
rhinitis was investigated. In the first part of the study, a new experimental nasal allergic late phase
eosinophilia model in Brown Norway (BN) rats was investigated. The increase in the number of
antigen inhalations resulted in the proportional increase in the number of inflammatory cells such as macrophages, eosinophils and neutrophils in the nasal cavity lavage fluid (NCLF) at 5 h after each inhalation. The number of inflammatory cells reached a maximum 8 h after the
antigen perfusion. Submaximum response was observed at 5 h after the
antigen provocation. In this system, the serum
IgG and
IgE antibody titers measured by homologous passive cutaneous anaphylaxis were 160 and 640, respectively. In the second part of the study, the effects of
prednisolone,
cetirizine and a newly synthesized amphoteric
antiallergic agent,
HSR-609, on this allergic late nasal
eosinophilia and neutrophilia in BN rats were investigated.
Prednisolone and
HSR-609 significantly inhibited the increase in the number of eosinophils in the NCLF but not
cetirizine. Furthermore,
prednisolone showed the inhibition of the increase in the number of macrophages and neutrophils in NCLF. These results suggest that this late phase
eosinophilia model in the nose of BN rats may be useful for investigating the therapeutic drugs for nasal
allergy and a newly synthesized amphoteric
antiallergic agent,
HSR-609, may be useful for the treatment of
allergic rhinitis with
eosinophilia.