Effect and mechanism of ligustrazine on the airway smooth muscle of isolated guinea pigs

Abstract

Objective To observe the effect and mechanism of Ligustrazine （ LIG ） on the Airway smooth muscle（ ASM） of isolated guinea pigs. Methods The normal guinea pig bronchus were made into tra-chea spiral,and randomly divided into LIG group, LIG＋Propranolol group, LIG＋Atropine, LIG＋Nifedipine group,LIG＋Glibenclamide group and the control group. The effect of different concentrations of LIG on the ASM was respectively observed in the resting tension and the high tension caused by histamine,and the ASM re-laxation rate were compared between each groups. Results （1）It had diastolic function for LIG on the isolated guinea pigs ASM in the resting tension and the high tension caused by histamine. （2）In the resting tension,com-pared with the group LIG,the diastolic function was antagonism by the concentration of LIG 10-7 -10-6. 5 mol/L in the group LIG＋Propranolo （P〈0. 05）. The diastolic function had no significant difference by the concentra-tion of LIG 10 -7.5 -10 -3 mol/L in the group LIG＋atropine and LIG＋Glibenclamide（P〉0. 05）. The diastolic function was improved remarkably by the concentration of LIG 10 -6 -10 -4 mol/L,in the group LIG＋Nifedip-ine （P〈0. 05）. （3）In the high tension caused by histamine,compared with the group LIG,the diastolic function was antagonism obviously by the concentration of LIG 10 -6. 5 - 10 -5 mol/L in group LIG＋Propranolol （ P〈0. 05）;The diastolic function had no significant difference by the concentration of LIG 10 -8 -10 -3 mol/L in group LIG＋atropine,and LIG＋Glibenclamide （P〉0. 05）;The diastolic function was improved remarkably by the concentration of LIG 10 -6.5 -10 -5 mol/L in group LIG＋Nifedipine （P〈0. 05）. Conclusion It has dias-tolic function for LIG on the isolated guinea pigs ASM in the resting tension and the high tension caused by his-tamine. The effect and mechanism may be related with the competitive exciting beta 2 receptor and the inhibitor of Ca2＋ internal flow. It provides a theoretical basis for the clinical application of LIG in treating asthma. Key words: Ligustrazine; Isolated guinea pigs; Airway smooth muscle; Mechanism