Abstract

The pharmacological properties of KP-136, an inhibitor of type I allergy, were studied in rat paw models. In four allergic responses, three of the immediate type and one delayed type, KP-136 (p.o.) produced potent inhibitions on the mast cell-mediated type I allergy (ID30 : 1.0 mg/kg) and the neutrophil-infiltrated passive Arthus reaction (ID30 : 1.6 mg/kg). In addition, KP-136 (10 mg/kg, 50 mg/kg, p.o.) inhibited the injury of bone tissues in rat adjuvant arthritis, confirming that it was effective on the allergic inflammation with tissue injury. Although KP-136 was a weak inhibitor of carrageenin-induced paw edema, prostaglandin synthesis and complement-mediated hemolysis, the compound inhibited the release of lysosomal enzymes such as lysozyme and β-glucronidase in the passive Arthus reaction, suggesting the blockage of inflammatory mediator release for its mode of action.