To explore the changes of leukotrienes (LT) in cerebral cortex and lung tissues in ovalbumin-induced rat asthma model and effects of different anti-asthma drugs on the changes. METHODS: Aerosol antigen-induced changes of inflammation in bronchoalveolar lavage fluids (BALF), pulmonary and brain histologic section in sensitized rats were investigated. Changes of LTB4 and LTC4 in lung and cerebral cortex homogenates were analyzed by reverse-phase high performance liquid chromatography (RP-HPLC). RESULTS: The number of inflammatory cells in BALF and the score of lung and brain histological examination from antigen- challenged rats were significantly higher than that from control group (P<0.05). Dexamethason (DXM, 0.5mg/kg, ip) and ketotifen fumarate (KF, 5mg/kg, ig) markedly reduced total leukocyte number in BALF, and inhibited eosinophil accumulation, reduced the infiltration of eosinophils, and improved mucous edema and epithelial lesion of bronchi and bronchioles. In addition, RP-HPLC results shown LTB4 in lung and cerebral cortex homogenates were increased in antigenchallenged rats [(4.1