【摘要】 目的 :探讨双氢杨梅树皮素对血管平滑肌的作用机制。方法 :采用家兔离体胸主动脉条标本 ,观察双氢杨梅树皮素对去甲肾上腺素 (NA)、氯化钾 (KCl)和氯化钙 (CaCl2 )所致收缩反应的剂量 -效应曲线的影响 ,同时与钙通道阻滞剂维拉帕米 (Ver)作比较研究。结果 :双氢杨梅树皮素能舒张已被NA、CaCl2 和高K+ 收缩的兔胸主动脉条 ,使NA、KCl、CaCl2 诱导的剂量 -效应曲线非平行右移 ,最大反应降低 ;这一作用与Ver相似 ,是通过阻钙通道实现的。但它们阻断钙通道的方式可能有所不同。双氢杨梅树皮素除了能阻断电压依赖的钙通道 (PDC) ,在较高浓度时还能阻断受体激活的钙通道 (ROC)。而Ver只选择性阻断PDC。结论 :双氢杨梅树皮素扩张血管的机制与其钙通道阻滞作用有关更多还原

【Abstract】 Objective: To elucidate the mechanism of vasodilatation of dihydromyricetin (Dih). Methods: The effects of Dih were studied on the contraction of isolated rabbit aortic strips agonized by noradrenaline (NA), KCl and CaCl 2. The fluctuation of the concentration-response curves was observed. Results: Dih was found to inhibit the contractions evoked by NA, KCl and CaCl 2 in rabbit aortic strips. Dih shifted the concentration-response curves of NA, KCl and CaCl 2 to the right, and depressed their maximal responses. Dih-induced relaxation on vascular smooth muscle resulted from its calcium channel blocking and the mode of this mechanism had some differences from that of Verapamil. Dih inhibited both the receptor operated channel and potential dependent channel. On the contrary, Ver inhibited the potential dependent channel only. Conclusion: The mechanism of vasodlatation of Dih is related to its blocking effect on calcium channel.更多还原