EFFECT OF LODOXAMIDE ON INVITRO AND INVIVO CONJUNCTIVAL IMMEDIATE HYPERSENSITIVITY RESPONSES IN RATS

The antiallergic compound, lodoxamide, was evaluated for its abilities to attenuate a local allergic reaction in rat conjunctiva in vivo and to inhibit rat conjunctival mast cell mediator release in vitro. Topically applied lodoxamide (0.01, 0.10 and 1.0%, w/v) dose-dependently reduced the allergic response (23, 43 and 72%, respectively) in vivo. Lodoxamide was more effective than cromolyn sodium, N-acetyl aspartyl glutamic acid (Naaxia(R)) and levocabastine, and 25 (7-200) times more potent than nedocromil sodium in direct comparisons. Addition of lodoxamide (10 mug/ml) to sensitized conjunctival tissue in vitro immediately prior to antigen challenge significantly reduced the amount of histamine released by the tissue. These data suggest that lodoxamide's in vivo antiallergic activity in the conjunctiva is associated with its ability to prevent allergic mediator release from mast cells contained in this same tissue.