摘要
用兔胸主动脉条研究双氢杨梅树皮素对去甲肾上腺素（NE）、KCl和CaCl2所致兔胸主动脉条收缩反应量效曲线的影响。双氢杨梅树皮素能显著地抑制NP、KCl和CaCl2所致兔胸主动脉杂的收缩，量效曲线右移，最大反应降低，对高K+所致兔胸主动脉条收缩的抑制作用明显大于NE所致兔胸主动脉条收缩的抑制作用。双氢杨梅树皮素对NE引起的依赖内Ca2+释放的收缩有明显抑制作用，而对NE依赖细胞外Ca2+性收缩区在较高浓度时才显示抑制作用，提示双氢杨梅树皮素可能对电压依赖性钙通道（PDC）有选择性阻滞作用。
The effects of dihyromyricetin (DIH) wcro studied on the contraction of rabitthoracic aorta stripes induced by norepinephrine (NE), KCl and CaCl2. DIH was found to depressthe contraction as demonstrated by the shift-to-rihgt of the dose-effect relationship curvesand the decrease of maximal responses. The degree inhibited to high k+ wa, more potent thanthat to NE. The intracellular Ca2+-depedent coynponent of NE-induced aortic sripe contractionwas also inhibited by the DIH, but the extracellular Ca2+-dependent component was barely ornot inhibited by DIH before it, concentration was raised to 4.0 mmol/L. These results indicatethat the depressive effect of DIH on aortic contraction is mainly exerted by acting on the PDC.
