摘要
目的:研究中成药华蟾素对大鼠离体胸主动脉环的作用及其机制。方法:采用大鼠离体胸主动脉灌流模型,观察华蟾素对血管张力的影响。结果:华蟾素(2.5、5.0、7.5、10.0 g/L)浓度依赖性地收缩去内皮的大鼠胸主动脉环,收缩幅度分别为(16.3±3.39)%、(52.5±7.70)%、(60.9±8.84)%、(69.2±11.34)%,显著高于内皮完整的大鼠胸主动脉环收缩幅度[(6.2±2.07)%、(14.7±4.91)%、(17.6±5.86)%、(20.3±6.78)%](P<0.01);在无Ca2+液中,10.0 g/L华蟾素对去内皮主动脉环的收缩幅度[(7.1±0.79)%]显著低于有Ca2+液中的收缩幅度[(78.1±4.32)%](P<0.01);维拉帕米(1-0 7m o l/L,V er)预处理可消除10.0 g/L华蟾素的缩血管作用(P<0.01);一氧化氮合酶抑制剂L-NAM E(1-0 4m o l/L)预处理内皮完整的主动脉环,可增强10.0 g/L华蟾素的缩血管作用(P<0.01)。结论:华蟾素对大鼠离体胸主动脉有收缩作用,其缩血管机制与其促使细胞外Ca2+经电压依赖性钙通道内流进入血管平滑肌细胞有关;同时,华蟾素作用于血管内皮细胞,引起血管舒张因子一氧化氮的释放,部分抵消其缩血管效应。
Objective： To examine the effect of cinobufacini on rat thoracic aorta and its mechanism. Methods： Isolated rat thoracic aorta was perfused and isometric tension was recorded by organ bath technique before and after cinobufacini treatment. Results： Cinobufacini induced contraction of isolated thoracic aorta with or without endothelium in a concentration-dependent manner （at concentration of 2.5, 5.0, 7.5, 10.0 g/L）. The vasoconstriction effect of cinobufacini was more potent in endothelium-denuded aorta ring [（16.3±3.39）%, （52.5±7.70）%, （60.9±8.84）%, （69.2±11.34）%] than in endothelium-intact aorta ring [（6.2±2.07）%, （14.7±4.91）%, （17.6±5.86）%, （20.3±6.78）%（P〈0.01）]. Its contractile effect was attenuated in Ca^2＋-free solution （about 1/10 of that in buffer with 1.25 mmol/L CaCl2） or by the treatment with verapamil （10^-7 mol/L）, an L-type calcium channel antagonist. Cinobufacini induced contraction on the endothelium-intact rat aorta was augmented by pretreatment with L-NAME （10^-4mol/L）, a nitric oxide synthase inhibitor. Conclusion： Cinobufacini contracts rat thoracic aorta by opening the voltage-dependent Ca^2＋ channel and increasing Ca^2＋ influx into vascular smooth muscle. Cinobufacini can also stimulate the release of vascular relaxant factor, nitric oxide, from the endothelium and thus antagonize cinobufacini-induced contraction.
出处
《浙江大学学报（医学版）》
CAS
CSCD
2006年第2期178-181,共4页
Journal of Zhejiang University(Medical Sciences)
基金
浙江省教育厅科研基金项目(20040205)
