钩藤碱对猪冠状动脉平滑肌舒缩作用的影响及其机制  

Mechanism of Rhynchophylline-induced relaxation in porcine coronary artery

作　　者：李鹏云[1] 杨艳[1] 程俊[1] 刘智飞[1] 裴杰[1] 周文[1] 曾晓荣[1] 

机构地区：[1]泸州医学院心血管医学研究所,四川泸州646000

出　　处：《重庆医学》2012年第16期1561-1563,1566,共4页Chongqing medicine

基　　金：国家自然科学基金资助项目(30370527)

摘　　要：目的观察钩藤碱对离体猪冠状动脉血管的作用,并探讨其作用机制。方法采用血管环张力测定技术及全细胞穿孔膜片钳技术分别观察钩藤碱对离体猪冠状动脉血管环张力的影响以及对大电导钙激活钾通道(BKCa)的作用。结果血管环张力实验显示钩藤碱能够明显舒张[(89.94±1.18)%,n=7]高钾(40mmol/L)去极化所致的冠状动脉血管收缩,而K+通道阻断剂四乙基胺(TEA)不能抑制钩藤碱的舒血管作用,提示K+通道几乎不参与钩藤碱对猪冠状动脉血管的舒张。在全细胞穿孔膜片钳模式下,钩藤碱(100μmol/L)可显著抑制猪冠状动脉平滑肌细胞的BKCa通道[(48.22±4.24)%,n=6],BKCa通道介导的自发性瞬时外向电流(STOCs)的幅度和频率也分别下降了(45.74±6.26)%和(87.98±6.39)%(n=5)。结论钩藤碱可明显舒张猪冠状动脉血管,而对全细胞BKCa通道具有明显的抑制作用,K+通道的激活在钩藤碱的舒血管机制中所起的作用不大。Objective To examine the effect of rhynchophylline （Rhy） on porcine coronary artery rings and to investigate the mechanism involved. Methods The isometric tension of coronary arterial rings taken from porcine hearts was measured and its response to Rhy（100 μmol/L）was studied. The effect of Rhy on BKca currents was observed by whole-cell perforated patch clamp configuration. Results Rhy（100 μmol/L） significantly antagonized[-（89.94±1.18）% ,n= 71 the coronary artery tension increase precontracted with KCI（40 mmol/L） ,K^＋ channels blocker TEA（10 retool/L） failed to prevent the relaxation effect of Rhy. Under the perforated whole-cell patch-clamp configuration, Rhy（ 100 μmol/L） significantly inhibited BKca currents[48.22 %± 4.24%, n = 61. The mean amplitude and frequency of spontaneous transient outward currents（STOCs） or transient BKca currents were also remarkably inhibited by （45.74±6.26）% and （87.98±6.39）%（n=5）,respectively. Conclusion Rhy relaxes reeontracted porcine coronary artery; K^＋ channel activation is almost not involved in coronary artery relaxation induced by Rhv.

关 键 词：钩藤属 钾通道 钙激活 肌 平滑 血管 冠状动脉 

分 类 号：R285.5[医药卫生—中药学]