荞麦花叶总黄酮的舒张血管作用及其机制  

Relaxant effects of total flavonoids of buckwheat flowers and leaves on rat thoracic aorta and underlying mechanisms

作　　者：张博男[1] 储金秀[1] 韩淑英[1] 

机构地区：[1]华北煤炭医学院基础部药理学教研室,河北唐山063000

出　　处：《中国药理学通报》2010年第7期952-956,共5页Chinese Pharmacological Bulletin

基　　金：河北省教育厅科技攻关资助项目(No2006320);唐山市"十一五"重点工程资助项目(No072631B-1)

摘　　要：目的探讨荞麦花叶总黄酮(TFBFL)对大鼠离体胸主动脉的舒张作用与机制。方法采用离体血管环灌流装置,经生物信号采集与分析系统测定血管环张力的变化;激光扫描共聚焦显微镜技术检测血管平滑肌细胞内钙浓度。结果在苯肾上腺素(phenylephrine,PE)10-6mmol.L-1或KCl60 mmol.L-1预收缩的保留内皮和去除内皮的血管环中,TFBFL均能够浓度依赖性的引起血管舒张;相对于去除内皮的血管环,TFBFL对保留内皮的血管环的舒张作用更明显。保留内皮的血管环用一氧化氮合酶抑制剂L-NAME(100mmol.L-1)预孵后,TFBFL诱导的血管舒张作用明显减弱。在无钙灌流液中,用KCl 60 mmol.L-1去极化去除内皮的血管环后,逐渐加入Ca2+,使血管环呈浓度依赖性收缩;TFBFL(0.8 mg.L-1)孵育10 min后可使CaCl2的量效曲线向下移位且可使PE在无钙灌流液中诱导的血管环最大收缩幅度明显降低。激光扫描共聚焦显微镜检测细胞内钙的结果表明,TFBFL浓度依赖性(0.4、0.8 mg.L-1)的抑制了静息状态平滑肌细胞质内钙浓度的升高。结论 TFBFL能够浓度依赖性舒张大鼠胸主动脉,其作用机制可能是降低细胞内游离Ca2+浓度;对于保留内皮的血管环,TFBFL也作用于血管内皮细胞,促进一氧化氮的释放,引起血管舒张。Aim To explore the vasodilative effect on rat thoracic aortic ring of total flavonoids of Buckwheat flowers and leaves（TFBFL） and the underlying mechanisms.Methods Isometric tension measurements were used to study the effect of TFBFL on isolated rat thoracic aorta rings.Laser scanning confocal microscope was employed to measure the concentration of intracellular free calciums.Results In aorta rings precontracted with phenylephrine or potassium chloride,TFBFL caused a dose-dependent relaxation in both endothelium-intact and denuded rings and the relaxant effect of TFBFL was more potent on endothelium-intact aorta rings than that on endotheliumdenuded aorta rings（〈P0.01）.The relaxant effect with endothelium was significantly attenuated when the preparation was pretreated with L-NAME（100 mmol·L-1）,a NOS inhibitor.Cumulative application of Ca2＋ induced a concentration-dependent contraction in rat aortic rings without endothelium in Ca2＋ free K-H solution pre-depolarized with KCl;Both Ca2＋-and PE-induced contraction were dramatically attenuated after pretreated with TFBFL（0.8 mg·L-1）for 10 min in Krebs solution without Ca2＋.TFBFL also dose-dependently decreased the intracellular free calcium concentration measured by laser scanning confocal microscope.Conclusions TFBFL exerts a dose-dependent vasodilative effect on rat isolated aorta rings and the possible underlying mechanism may be involved in the reduction of intracellular Ca2＋ mobilization.TFBFL may also stimulate the release of nitric oxide from endothelium cells which can partly induce the vasodilative effect.

关 键 词：荞麦花叶总黄酮 血管舒张 一氧化氮 钙通道 胸主动脉环 激光扫描共聚焦显微镜 

分 类 号：R-332[医药卫生] R284.1