The effect of a cysteinyl leukotriene antagonist, ONO-1078 (pranlukast) on agonist- and antigen-induced nasal microvascular leakage in guinea pigs.

The in vivo model of nasal microvascular leakage was used for the nasal allergic challenge in ovalbumin (OA)-sensitized guinea pigs, or nasal stimulation with leukotriene D4 (LTD4) in non-sensitized animals. An intravenous injection of Evans blue dye was given as an index of nasal microvascular leakage. Following the nasal stimulation with LTD4, the concentration of dye in the nasal lavage fluid rapidly increased. Oral administration of ONO-1078 (pranlukast) (3-30 mg/kg) significantly inhibited the LTD4-induced nasal microvascular leakage. In OA-sensitized guinea pigs, the excretions of dye into nasal lavage fluid were recognized soon after the topical antigenic stimulation and continued for over 60 minutes. Oral administration of ONO-1078 (30 mg/kg) significantly inhibited the antigen-induced microvascular leakage. These results suggest that ONO-1078 may be of therapeutic use for nasal allergy.