EFFECTS OF HISTAMINE H-1 RECEPTOR ANTAGONISTS ON COMPOUND 48 80-INDUCED SCRATCHING BEHAVIOR IN MICE/

The effects of histamine H-1 receptor antagonists on compound 48/80-in duced scratching behavior were studied in mice. Classical histamine H- 1 receptor antagonists such as diphenhydramine and chlorpheniramine ca used a potent depressant effect on compound 48/80-induced scratching b ehavior. Histamine H-1 receptor antagonists having antiallergic activi ty (an inhibition of mast cell degranulation), such as azelastine and oxatomide and nonsedative histamine H-1 receptor antagonists such as t erfenadine, epinastine and astemizole, also showed a relatively potent effect. On the other hand, the effects of tranilast and cromolyn sodi um-antiallergic drugs without histamine H-1 receptor antagonistic acti vity-were extremely weak. Diazepam had weak or no depressant effects o n compound 48/80-induced scratching behavior. These results suggest th at inhibition of compound 48/80-induced scratching behavior is mainly due to histamine H-1 receptor antagonistic activity and not to the sed ative action of the drugs. (C) 1998 Elsevier Science B.V. All rights r eserved.