Proposal of the new concepts of antiallergic drugs from the results of animal experiments

According to the previous concepts of antiallergic drugs, it was difficult to select the essential antiallergic drugs which was necessary for treatment of patients with allergy. We, therefore, attempted to discover that antiallergic drugs have the any pharmacologic actions on the process of allergic response. We divided into three stages on the process of allergic response in this animal experiment. Antiallergic drugs used in this study were azelastine hydrochloride, ketotifen fumarate, tranilast and oxatomide. First, we observed the suppression of IgE production in rats on the administration of azelastine hydrochloride. Secondly, we observed that azelastine hydrochloride and ketotifen fumarate inhibited the interaction between anti-DNP-As and DNP-As on ELISA. Thirdly, we observed that tranilast and azelastine hydrochloride reduced, more effectively than any other antiallergic drug, the release of histamine from rabbit washed platelets by PAF.In addition, it was observed that azelastine hydrochloride and ketotifen inhibited dose-dependently the increase of permeability induced by PAF or histamine in rats. From these results, we could propose the new concepts that some of antiallergic drug inhibited the IgE production.