3种钾通道在哮喘豚鼠气道高反应中的作用  

Role of three kinds of potassium channel in airway hyperresponsiveness of asthmatic guinea pigs

作　　者：邓世苇[1] 叶红[1] 金肆[1] 叶仕桥[1] 王迪浔[1] 

机构地区：[1]华中科技大学同济医学院病理生理学系,湖北武汉430030

出　　处：《中国病理生理杂志》2005年第10期1970-1973,共4页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.39770309)

摘　　要：目的:探讨钙激活钾通道(KCa)、延迟整流型钾通道(Kdr)和ATP敏感型钾通道(KATP)在哮喘豚鼠气 道高反应中的作用。方法:采用离体气管环张力实验,观察加入特异性钾通道阻断剂后,与不加阻断剂相比气管环 对组胺反应的量效曲线的差异。结果:(1)加入KCa阻断剂TEA后,对照组气管环对组胺的反应变化不显著,而哮喘 组气管环对10-4mol／L、10-3mol／L组胺的收缩反应均显著低于不加TEA的气管环(P<0．01),量效曲线明显下移; (2)加入Kdr阻断剂4-AP后,对照组气管环对10-3mol／L组胺的最大收缩反应明显下降(P<0．05),组胺的量效曲线 下移,哮喘组气管环对10-4mol／L、10-3mol／L组胺的收缩反应均低于不加4-AP的气管环(P<0．01),且下降程度较 对照组大(P<0．05),量效曲线明显下移;(3)加入KATP阻断剂glibenclamide后,对照组和哮喘组气管环对组胺的量效 曲线与不加glibenclamide的气管环相比变化均无明显差异。结论:在豚鼠哮喘模型中,KCa和Kdr活性的降低在气道高 反应的发生中起介导作用,KATP作用不明显。AIM： To investigate the role of Ca^2＋ - activated, delayed - rectifier and ATP sensitive K^＋ channel （KCa^＋ Kdr, KATe） in airway hyperresponsiveness of asthmatic guinea pigs. METHODS： The method of recording the tone of isolated trachea tings was performed, and the changes of dose - response curves of trachea rings to histamine caused by different K^＋ channel blockade were investigated. RESULTS： （1） After inhibition of KCa by tetraethylammonium （TEA）, the dose- response curve of trachea rings to histamine did not change in control group, while the maximal contraction of trachea rings to 10^-4 mol/L and 10^-3 mol/L histamine decreased significantly （ P 〈 0.01 ） and dose - response curve shifted down significantly in asthmatic group. （2） After inhibition of Kdr by 4 - aminopyridine （4 - AP）, the maximal contraction to 10^-3 mol/L histamine decreased （ P 〈 0.05） and dose-response curve shifted down in control group, the response to 10^-4 mol/L and 10^-3 mol/L histamine decreased significantly （ P 〈0.01） and dose- response curve shifted down more significantly in asthmatic group and the decrease of the latter was more significant than that in control group （P 〈0.05）; （3） The dose- response curves did not change by KATe blocker glibenclamide （Glib） in both control and asthmatic group. CONCLUSION： The depression of both KCa and Kdr might mediate the airway hyperresponsiveness in asthmatic guinea pigs, whereas the KATe doesn＇ t take part in it.

关 键 词：哮喘 气道高反应 钾通道 钙激活 钾通道 延迟整流 钾通道 ATP敏感 

分 类 号：R363[医药卫生—病理学]