Effect of TYB-2285 on lung anaphylaxis in actively sensitized rats.

Abstract 1. 1. We examined the effect of TYB-2285 on the acute phase and the late phase of lung anaphylaxis in rats. 2. 2. TYB-2285 (3-30 mg/kg PO) inhibited antigen-induced bronchoconstriction and TxB 2 production during the acute phase of lung anaphylaxis in a dose-dependent manner. 3. 3. Ketotifen fumarate (30 mg/kg PO) inhibted bronchoconstriction and TxB 2 production less potently than TYB-2285. 4. 4. TYB-2285 (30 mg/kg PO) inhibited the accumulation of neutrophils during the late phase of lung anaphylaxis significantly without a significant change in total cells. 5. 5. Hydrocortisone acetate (100 mg/kg PO) inhibited the accumulation of total cells as potent as neutrophils.