内皮衍生超极化因子在冠状动脉反应性充血扩张中的作用的实验研究  

Role of endothelium-derived hyperpolarizing factor in coronary vasodilation induced by reactive hyperemia in dogs

作　　者：李天亮[1] 邓又斌[1] 王林[1] 杨好意[1] 毕小军[1] 潘敏[1] 白姣[1] 常青[1] 黎春雷[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院超声影像科,湖北武汉430030

出　　处：《中国医学影像技术》2005年第10期1480-1483,共4页Chinese Journal of Medical Imaging Technology

基　　金：国家自然科学基金项目资助(30270560)。

摘　　要：目的评价内皮衍生超极化因子(EDHF)在血流介导性冠状动脉反应性充血扩张中的作用。方法健康成年杂种犬10条。冠状动脉内注射钾离子通道阻断剂四乙铵(TEA)以抑制EDHF的作用前后,应用超声心动图仪分别观察记录反应性充血试验诱发的冠状动脉左前降支(LAD)内径的变化以及心肌内冠状动脉(I MCA)血流的变化。测量LAD内径、I MCA的峰值血流速度(Vmax)及流速时间积分(VTI),并计算反应性充血试验诱发的百分变化率。结果冠状动脉内注射TEA前后反应性充血试验诱发的LAD内径百分变化率的差异无显著性意义[(12.29±2.61)%vs(10.31±2.89)%,P=0.123]。冠状动脉内注射TEA后反应性充血试验诱发的I MCA的Vmax、VTI的百分变化率却较注射TEA前明显减低[分别为(38.91±17.32)%vs(80.18±11.03)%及(26.50±12.61)%vs(75.86±21.77)%,P均<0.001]。结论应用TEA抑制EDHF的作用对血流介导性正常犬心外膜冠状动脉扩张反应无明显影响,而使I MCA反应性充血程度减小,提示EDHF在大、小冠状动脉的作用不同,EDHF在I MCA内皮血流依赖性扩张反应中起一定作用。Objective To evaluate the role of endothelium-derived hyperpolarizing factor （EDHF） in flow-dependent coronary vasodilation induced by reactive hyperemia （RH）. Methods In ten instrumented dogs, the changes in internal diameter of the left anterior descending （LAD） coronary artery and intramyocardial coronary artery （IMCA） flow were investigated before and after RH under the condition with and without intracoronary infusion of tetraethylammonium （TEA）, a Kc, channel blocker, as an inhibitor of EDHF. Internal diameter of LAD, maximal velocity （Vmax） and velocity-time integral （VTI） of IMCA were measured using echoeardiography. The percent changes in internal diameter of LAD, Vmax and VTI of IMCA induced by RH under the condition with and without intracoronary infusion of TEA were calculated. Results The percent change in internal diameter of LAD in response to RH after intracoronary infusion of TEA did not change significantly when compared with that before intracoronary infusion of TEA [（10.31±2.89）% vs （12.29±2.61）%, P=0.123]. However, the percent changes in Vmax and VTI of IMCA in response to RH with intraeoronary infusion of TEA were dramatically lower than that without intracoronary infusion of TEA [（38.91±17.32）% vs （80. 18±11.03）%, P〈0.001 ; （26.50±12.61）% vs （75.86±21.77）%, P〈0. 001 respectively]. Conclusion Blockade of EDHF with TEA has no significant influence on flow-dependent dilation of LAD. However, it reduces flow-dependent intramyocardial coronary vasodilation induced by reactive hyperemia. This indicates that vascular endothelium contributes flow-dependent dilation of IMCA induced by RH through EDHF formation.

关 键 词：超声心动描记术 内皮衍生超极化因子 冠状血管 内皮 血管 

分 类 号：R540.45[医药卫生—心血管疾病] Q95-33[医药卫生—内科学]