桂利嗪与尼莫地平对离体血管的舒张作用

Different relaxation effect of cinnarizine and nimodipine on isolated arteries

目的:比较桂利嗪与尼莫地平对于离体血管的舒张作用。方法:分离SD大鼠胸主动脉,在内皮完整及去内皮的血管环上分别加入桂利嗪及尼莫地平,以累积剂量法给药至最大舒张剂量,观察药物对两种离体血管的舒张作用。结果:尼莫地平与桂利嗪均能剂量依赖性舒张内皮完整及去内皮血管。尼莫地平对内皮完整血管的舒张作用强于去内皮血管的舒张作用。桂利嗪对去内皮血管的舒张作用与内皮完整血管的作用相似。结论:尼莫地平的扩血管作用部分为内皮依赖性的,部分为对平滑肌的直接扩张作用;桂利嗪的扩血管作用主要是通过对平滑肌的直接扩张作用实现的。

Objective ： This study was designed to investigate the different relaxation effect of cinnarizine and nimodipine on isolated arteries. Methods ： Arteries were isolated from sixteen male Sprague-Dawley rats weighing 220 - 250 g, carefully dissected from surrounding fat and connective tissues, and cut into 2 - 3 mm-long circular segments. These segments were initially eontraeted with phenylephrine （1 μM）. When the contraction reached a steady state, cumulative concentration-response （CR） curves to cinnarizine or nimodipine were obtained by adding increasing concentrations to the segments thai functional endothelium was present or absent. Resuits：Both cinnarizine and nimodipine produced concentration-dependent relaxation on the segments that functional endothelium was present or absent. Nimodipine produeed stronger relaxation on endothelium complete segments than on the endothelium removal ones. Cinnarizine produced a same relaxation on endothelium-complete segments and endothelium-removed ones. Conclusion： Cinnarizine and nimodipine produced different relaxation effeets on endothelium-complete segments and endothelium - removed ones. The difference between cinnarizine and nimodipine was depended on the integrity of the vascular endothelium.