ABSTRACT
Objective To investigate the effect of daurinoline on basilar artery vascular smooth muscle. Methods The tension of isolated basilar artery ring of rabbit was measured. The effects of daurinoline on the basilar artery contracted by methoxamine,5-hydroxytryptamine(5-HT),KCl and Histamine( His)were also examined. Dose-response curves of 5-HT and KCl were observed as well. Results Daurinoline exerted obvious relaxation effect on the basilar artery vascular ring contracted by methoxamine,5-HT,KCl and His in a concentration-dependent manner. IC50 of daurinoline in methoxamine,5-HT,KCl and His-treated rabbits was 8.67×10-5,1.78×10-6,6.79×10-7 and 4.98×10-4 mol·L-1,respectively. The change of concentration-response curves of methoxamine,5-HT,KCl and His showed that daurinoline was a non-competitive antagonist. Conclusion Daurinoline exerts marked relaxation effect on basilar artery of rabbits through non-competitive antagonism. The mechanism of relaxation action may be related to blockage of voltage-dependent or receptor-dependent calcium channels.