盐酸埃他卡林扩血管特征的研究

Vasodilating characteristics of iptakalim hydrochloride

目的 观察新型抗高血压药盐酸埃他卡林对大、小动脉扩张作用的药理学特征。方法 采用大鼠主动脉离体血管环和尾动脉螺旋状血管条两种组织来对比分析盐酸埃他卡林的扩血管作用。结果 盐酸埃他卡林在 10 -7～ 10 -3 mol/L范围内对氯化钾预致收缩的大鼠尾动脉血管条产生剂量依赖性舒张反应 ,且具有部分内皮依赖性 ,但对主动脉离体血管环无明显的舒张反应 ,该作用在高血压状态时显著增强 ,能被ATP敏感性钾通道特异性阻断剂格列苯脲阻断。结论 盐酸埃他卡林具有选择性舒张小动脉的作用 ,该作用与其激活ATP敏感性钾通道有关。

Objective To observe the pharmacological characteristics of a novel antihypertensive drug iptakalim hydrochloride (Ipt) by dilating large and small arteries. Methods The vasodilating action of Ipt was studied using isolated rat tail artery helical strips and aortic rings. Results The vasodilating action of Ipt at 10 7-10 3mol/L was observed in rat tail artery strips precontracted with potassium chloride (KCl) in a concentration and endothelium dependent manner, but no significant vasodilating effect was seen on rat aortic rings. Ipt-induced relaxation in tail artery was significantly greater in spontaneous hypertensive rats than that in normotensive rats. The vasodilating actions of Ipt in small arteries could be markedly antagonized by glibenclamide, an inhibitor of ATP-sensitive potassium channels. Conclusion The results suggest that iptakalim hydrochloride has a selective vasodilating action in small arteries, and the action is related to activation of ATP-sensitive potassium channels.