Scutellarin-induced Endothelium-independent Relaxation in Rat Aorta
Scutellarin-induced Endothelium-independent Relaxation in Rat Aorta
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DOI：
10.1002/ptr.2364
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发表时间：
2008-11-01
影响因子：
7.2
通讯作者：
Yang, Baofeng
中科院分区：
文献类型：
--
作者：
Pan, Zhenwei;Feng, Tieming;Yang, Baofeng
灯盏乙素是从中药灯盏花中提取的一种黄酮类化合物。本研究采用离体大鼠主动脉模型，探讨灯盏乙素的舒张作用及其机制。灯盏乙素（3，10，30，1001 μ M）引起的剂量依赖性舒张在内皮完整和内皮剥脱大鼠主动脉环预收缩去甲肾上腺素酒石酸氢盐（IC 50 = 7.7 +/- 0.6 μ M），但不与氯化钾。四乙铵、格列本脲、阿托品、普萘洛尔、吲哚美辛和N（G）-硝基-L-精氨酸甲酯对灯盏乙素的血管舒张作用无影响，进一步排除了钾通道、M受体、一氧化氮途径和前列腺素参与灯盏乙素的血管舒张作用。灯盏乙素预处理降低紧张相，但不去甲肾上腺素酒石酸氢盐诱导的张力增加的相位。在电压依赖性钙通道阻滞剂维拉帕米存在下，灯盏乙素还减轻了Ca 2 +-耗尽/重酒石酸去甲肾上腺素预处理环中Ca 2 +-诱导的血管收缩。重酒石酸去甲肾上腺素引起的细胞内钙升高可被灯盏乙素抑制。灯盏乙素对佛波醇-12，13-二乙酸酯在无钙浴溶液中诱导的收缩没有影响。结果表明，灯盏乙素具有非内皮依赖性舒张胸主动脉环的作用。其机制可能是抑制细胞外钙离子内流，而不依赖于电压依赖性钙通道。版权所有（C）2008约翰威利父子有限公司
Scutellarin is a flavonoid extracted from the traditional Chinese herb, Erigeron breviscapus Hand Mazz. In the present study, the vasorelaxant effects of scutellarin and the underlying mechanism were investigated in isolated rat aorta. Scutellarin (3, 10, 30, 1001 mu M) caused a dose-dependent relaxation in both endothelium-intact and endothelium-denuded rat aortic rings precontracted with noradrenaline bitartrate (IC50 = 7.7 +/- 0.6 mu M), but not with potassium chloride. Tetraethylammonium, glibenclamide, atropine, propranolol, indomethacin and N(G)-nitro-L-arginine methyl ester had no influence on the vasorelaxant effect of scutellarin, which further excluded the involvement of potassium channels, muscarinic receptor, nitric oxide pathway and prostaglandin in this effect. Pretreatment with scutellarin decreased the tonic phase, but not the phasic phase of the noradrenaline bitartrate induced tension increment. Scutellarin also alleviated Ca2+-induced vasoconstriction in Ca2+-depleted/noradrenaline bitartrate pretreated rings in the presence of voltage-dependent calcium channel blocker verapamil. The noradrenaline bitartrate evoked intracellular calcium increase was inhibited by scutellarin. Scutellarin had no effect on phorbol-12,13-diacetate induced contraction in a calcium-free bath solution. These results showed that scutellarin could relax thoracic artery rings in an endothelium-independent manner. The mechanism seems to be the inhibition of extracellular calcium influx independent of the voltage-dependent calcium channel. Copyright (C) 2008 John Wiley & Sons, Ltd.