ABSTRACT
AIM: To evaluate the antihistamine effects of domestic azelastine hydrochloride. METHODS: Histamine increased skin vascular permeability and induced shock model in guinea pigs. In isolated guinea pig ileal rings, the contraction of smooth muscle induced by histamine was determined. RESULTS: Pretreament with azelastine hydrochloride( 0.05, 0.15,and 0.45 mg?kg -1,ig) significantly inhibited the increase in skin vascular permeability induced by histamine in a dose-dependent manner in guinea pigs. Pretreament with azelastine hydrochloride( 0.05, 0.1,and 0.2 mg?kg -1,ig)produced a significant improvement of shock, as shown by a decrease in reactivity degree, mortality and a prolongation of latency. In isolated guinea pig ileal rings, azelastine hydrochloride (10 -8,3?10 -8,10 -7,3? 10 -7 mol?L -1)significantly inhibited contraction of smooth muscle induced by histamine in a concentration-dependent manner and caused a parallel right shift of the dose-effect curve of histamine (pA 2= 8.55). CONCLUSION: Domestic azelastine hydrochloride shows significant the antihistamine effects.