满山红水提物对大鼠离体胸主动脉的舒张作用与机制  

Relaxant Effect of Water Extract of Rhododendron dauricum on Rat Thoracic Aorta and Its Mechanisms

作　　者：王晓燕[1] 侯云龙[2] 

机构地区：[1]东北林业大学,哈尔滨150040 [2]哈尔滨医科大学

出　　处：《东北林业大学学报》2009年第8期64-66,共3页Journal of Northeast Forestry University

基　　金：国家科技支撑计划项目(2006BAD27B05)

摘　　要：采用离体大鼠胸主动脉环张力测定方法,观察满山红水提物(RWE)对大鼠离体胸主动脉的舒张作用与机制,研究结果表明:满山红水提物(RWE)能够浓度依赖性的降低主动脉环张力,对苯肾上腺素(phenyleph-rine,PE)预收缩的保留内皮血管环的最大舒张幅度明显强于对去除内皮血管环的作用;预孵一氧化氮合酶抑制剂L-NAME300mmol.L-1后,RWE对保留内皮的血管环的最大舒张幅度明显降低;预孵钾通道阻断剂4-AP和TEA各1mmol/L后,RWE引起的血管最大舒张幅度明显降低。在无钙灌流液中,用2g/LRWE孵育10min可使CaCl2的量效曲线下移且使PE的最大收缩幅度降低。可见,RWE能够浓度依赖性舒张大鼠胸主动脉,其作用机制可能是抑制细胞内钙离子浓度升高,促使电压敏感型K+通道(Kv)和Ca2+激活的钾离子通道(KCa)开放引起K+外流;同时,RWE也作用于血管内皮细胞,促进一氧化氮的释放。An experiment was conducted to study the relaxant effect of Rhododendron dauricum L. water extract （RWE） on rat thoracic aorta and its underlying mechanism. Isometric tension measurements were used to study the effect of R. dauricum on isolated rat thoracic aorta rings. Laser scanning corffocal microscope was employed to measure the concentration of intracellular free calcium. RWE caused a dose-dependent relaxation, and the relaxant effect of RWE was stronger on endotheliurn-intact aortic rings than on endothelium-denuded aortic rings. The maximal relaxant effect with endothelium was obviously attenuated pretreated with L-NAME （ 300 mmol · L ^- 1 ）, while that without endothelium was obviously degraded incubated with 4-AP （1 mmol/L） and TEA （1 mmoL/L）. PE induced contraction was obviously attenuated after pretreated with RTF （2 g/L） for 10 minutes in Krebs solution containing 10-4 tool EGTA without Ca^2＋. RWE exerted a dose-dependent vasorelaxant effect on rat isolated aortic rings by inhibiting influx of Ca^2 ＋ via L-type vohage-dependent Ca^2 ＋ channels, activated voltage-dependent K ^＋ channel and Ca^2 ＋ -activate K^＋ channel, and encouraged K^ ＋ efflux. RWE might also stimulate the release of nitric oxide from endothelium cells which can partly induce the relaxant effect.

关 键 词：满山红水提物 血管舒张 钙通道 胸主动脉环 

分 类 号：R9[医药卫生—药学]