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[摘要]
目的 探讨汉黄芩素增强乙酰胆碱对大鼠胸主动脉血管的舒张作用及其作用机制。方法 实验分为对照组和加药组,加药组使用含有不同浓度汉黄芩素的DMEM/F12培养基作用;对照组使用含有与加药组相同体积二甲基亚砜(DMSO)的DMEM/F12培养基作用。汉黄芩素孵育大鼠心脏微血管内皮细胞24 h,MTT法检测细胞活力;硝酸还原酶法检测细胞上清NO含量;ELISA法检测细胞内皮型一氧化氮合酶(eNOS)蛋白表达。汉黄芩素孵育大鼠胸主动脉环24 h,去甲肾上腺素(1×10-6 mol/L)收缩血管后应用乙酰胆碱(1×10-8、1×10-7、1×10-6、1×10-5 mol/L)舒张血管,检测血管张力变化。结果 与对照组比较,汉黄芩素处理细胞后,各组细胞活力没有显著变化。与对照组比较,汉黄芩素(5、20 μmol/L)显著促进NO的产生(P<0.01),但亚硝基左旋精氨酸甲酯(L-NAME)可以抑制汉黄芩素的这种作用(P<0.01)。汉黄芩素(0.5、5、20μmol/L)可以浓度相关性地促进心脏微血管内皮细胞eNOS蛋白表达,与对照组比较,汉黄芩素产生的eNOS蛋白水平差异非常显著(P<0.01)。乙酰胆碱(1×10-8、1×10-7、1×10-6、1×10-5 mol/L)能够浓度相关性地舒张离体大鼠胸主动脉环。与对照组比较,汉黄芩素(20μmol/L)孵育血管24 h,能显著增加乙酰胆碱对大鼠胸主动脉血管环的舒张程度,降低胸主动脉血管环的收缩率(P<0.01、0.05)。结论 汉黄芩素可能通过促进血管内皮细胞eNOS蛋白表达和NO产生这一途径增强乙酰胆碱对血管的舒张作用。
[Key word]
[Abstract]
Objective To study the effect of wogonin induced by acetylcholine on the vasodilation of rat thoracic aorta and explore its mechanism. Method The experiments were divided into control group and medication group. The medication group was treated with DMEM/F12 medium containing different concentrations of wogonin, while the control group was treated with DMEM/F12 medium containing the same volume of DMSO as the medication group. Rat cardiac microvascular endothelial cells were incubated with wogonin treated for 24 h. Cell viability was measured by MTT assay, NO content was measured by nitrate reductase assay, and eNOS protein expression was detected by ELISA method. The thoracic aortic rings of rats were incubated with wogonin treated for 24 h, NE (1×10-6 mol/L) was used to constrict blood vessels, and the acetylcholine (1×10-8, 1×10-7, 1×10-6, and 1×10-5 mol/L) was used to relax blood vessels to detect the changes of vascular tension. Results Compared with the control group, there was no significant changes of the cell viability in each group after treatment with wogonin. Compared with the control group, wogonin (5, 20μmol/L) significantly promoted NO production (P<0.01), but L-NAME could inhibit the effect of wogonin (P<0.01). Wogonin (0.5, 5, 20 μmol/L) could promote eNOS protein expression in cardiac microvascular endothelial cells in a concentration-dependent manner. Compared with the control group, the level of eNOS protein produced by wogonin was significantly different (P<0.01). Acetylcholine (1×10-8, 1×10-7, 1×10-6, and 1×10-5 mol/L) could dilate isolated rat thoracic aortic rings in a concentration-dependent manner. Compared with the control group, wogonin (20 μmol/L) incubated for 24 h significantly increased the relaxation of the thoracic aortic rings and decreased the contraction rate of the thoracic aortic rings in rats (P<0.01, 0.05). Conclusion Wogonin may enhance vasodilation of acetylcholine by promoting expression of eNOS protein and NO production in vascular endothelial cells.
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[基金项目]
国家自然科学基金资助项目(81603648,81803829)