藏药1号水提液对大鼠离体胸主动脉条收缩作用的影响

目的：通过观察藏药1号水提液对大鼠离体胸动脉条收缩作用的影响研究其降压机制。方法：观察藏药1号水提液(6mg／mL)和维拉帕米(Ver0.013mg／mL)对高K^ 液引起的主动脉条收缩的时效影响，对KCl，NE及CaCl2引起的大鼠主动脉条收缩的量效曲线的影响，以及对NE引起的依赖于细胞内钙及细胞外钙的收缩的影响。结果：藏药1号水提液抑制高K^ 液引起的主动脉收缩；且可使KCl、NE及CaCl2引起的大鼠主动脉条收缩的量效曲线非平行右移，最大效应降低，呈非竞争性拮抗作用：与维拉帕米相似，对NE引起的依赖于细胞内钙及细胞外钙的收缩均有抑制作用。结论：提示藏药1号的降压机制与钙离子通道拮抗剂一致。

Effect of aqueous extract from ZangYao-I on contractions in isolated rat thoracic aortic rings

Objective: To study the influence of aqueous extract from ZangYao-I(AEZY-I) on inhibition to the contractions induced by KCl, NE, CaCl_2 in isolated rat thoracic aortic rings, and uncover the mechanism of antihypertensive effect of ZanyYao-I. Methods: Recording the dose-response curves induced by KCl, NE, CaCl_2, and the next dose-response curves again after AEZY-I being added, respectively. Results: AEZY-I inhibited the contractions evoked by KCl, NE, CaCl_2 in isolated rat thoracic aortic rings. Significantly, AEZY-I could depress the maximal response and cause rightward displacement of the dose-response curves, and resulted of a non-competitive antagonism mechanism. In Ca 2+ free solution, AEZY-I inhibited contraction in aortic rings, which is dependent on Ca 2+ relased from not only intracellular store but also extracellular Ca 2+ . Therefore, AEZY-I inhibited both the potential dependent channel and the receptor operated channel. Conclusion: AEZY-I could relax the contraction of isolated rat thoracic aortic rings, and so the mechanism of antihypertensive of ZangYao-I is related to its antagonistic effect on calcium ion.