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本文研究了CY对家兔离体血管平滑肌的舒张作用.采用家兔离体胸主动脉为标本研究CY的舒血管作用.CY(3×10-3 mM-3 mM)可以舒张由肾上腺素、去甲肾上腺素、高钾和BaCl2引起收缩的血管平滑肌,EC50值分别为0.31±0.11,0.19±0.03,0.20±0.04和0.25±0.04 mM.CY(0.01 mM、0.1 mM、1 mM)剂量依赖性地抑制NE、KCl或CaCl2引起的的累积收缩鼍效曲线并呈非竞争性.在无钙液中CY能剂量依赖性的减弱由NE引起的位相性(第一时相)收缩,与维拉帕米有相似作用.因此,CY可能是通过阻断电压依赖性Ca2+通道舒张胸主动脉环.抑制细胞内钙的释放可能是CY主要的血管舒张作用机制之一.“,”The purpose of this study was to examine the relaxation effect of CY on the vascular smooth muscle (VSM) from rabbits. Experiments were carried out on isolated thoracic aorta of rabbits. CY (3 × 10 3mM - 3 mM) could relax the VSM preparations pre-contracted by adrenaline (AD), noradrenaline (NE), high-K+ solution or BaCl2 with respective EC50 values of (0.31±0.11) mM, 0.19±0.03 mM, 0.20±0.04 mM and 0.25±0.04 mM. Moreover, CY (10-2 mM, 0.1 mM and 1 mM) inhibited norepinephrine (NE),CaCl2 and KCl-induced vasoconstriction in a concentration dependent manner. The phasic contraction produced by NE was concentration dependently attenuated with CY (10-2 mM, 0.1 mM and 1 mM) in calcium-free medium, similar to that caused by verapamil. The present fmdings suggest that CY relaxed thoracic aortic rings by blocking voltage-dependent Ca2+ channels. The inhibition of intracellular Ca2+ release may be one of the main vasorelaxant mechanisms of CY.