NEDOCROMIL SODIUM INHIBITS AIRWAY HYPERRESPONSIVENESS AND EOSINOPHILIC INFILTRATION INDUCED BY REPEATED ANTIGEN CHALLENGE IN GUINEA-PIGS

1 Repeated exposure to ovalbumin aerosol produced significant increases in epithelial eosinophils of airways of all sizes and produced increased pulmonary resistance (R(L)) to inhaled acetylcholine (ACh) in guinea-pigs. 2 Nedocromil sodium 10 mg ml-1, by nebulization prior to each ovalbumin (OA) challenge inhibited both the airway eosinophilia and hyperresponsiveness to ACh. 3 Nedocromil sodium pretreatment (10 mg ml-1 by nebulization) 10 min prior to OA completely inhibited the acute bronchoconstrictor response to OA. 4 Our findings suggest that nedocromil sodium inhibits airway hyperresponsiveness by inhibiting eosinophilic infiltration, or by simultaneously inhibiting mechanisms involved in both processes.