比索洛尔对离体大鼠胸主动脉张力的作用

目的观察比索洛尔对离体大鼠胸主动脉环经KCl、NE预收缩血管的作用,并探讨其作用机制。方法记录大鼠离体胸主动脉环张力变化。结果累积浓度的比索洛尔对NE预收缩的血管环产生浓度依赖性舒张作用;对KCL预收缩的血管环,比索洛尔未产生明显的张力变化。在去内皮的主动脉环,NE预收缩后,累积浓度的比索洛尔产生浓度依赖性舒张作用,与内皮完整组比较无统计学差异。结论比索洛尔对NE预收缩血管有浓度依赖性的舒张作用,而KCL预收缩后,比索洛尔无作用。比索洛尔的舒张作用不具有内皮依赖性。

Effect of Bisoprolol on vascular responses of thoracic aorta in rats

Objective To investigate the effects and the possible mechanism of bisoprolol on isolated thoracic aorta rings pre-contracted by norepinphrine（NE） or potassium chloride（KCl）.Methods Rings of the isolated rat thoracic aorta were mounted in organ baths and isometric contractile force was measured. Results Bisoprolol respectively concentration-dependently reduced the contraction induced by NE,and had no effect on the contraction induced by KCL.Bisoprolol respectively concentration-dependently reduced the contraction of denude-endothlium aortic rings which induced by NE.There was no significant difference between the rings with intact and denude endothelium （P〉0.05）.Conclusion Bisoprolol could produce remarkable vasodilatation on NE pre-contracted aorta rings in rats. It＇s relaxtion effect isn＇t via endothelium-dependent mechanisms.