氯离子通道阻断剂对豚鼠离体气管条收缩的影响

目的 研究氯离子通道阻断剂对豚鼠离体气管条收缩反应的影响及其作用机制。方法 制备离体孵育的豚鼠气管条,分别在浴液中加入药物,测定KCl和5－羟色胺（5－HT）收缩气管条的作用以及氯离子通道阻断剂和维拉帕米（Ver)对KCl和5－HT作用的影响。结果 两种氯离子通道阻断剂氮氟灭酸（NFA）和5－硝基－2－3苯酚丙胺苯甲酸盐（NPPB）均能使KCl或5－HT引起的气管条收缩显著抑制,解痉百分率分别为100％和30％,Ver的抑制效应位于NFA与NPPB之间,NFA,NPPB和Ver对细胞内Ca^2 释放和细胞外Ca^2 内流引起的收缩均有抑制作用。结论 氯离子通道阻断剂NPPB和NFA可抑制KCl和5－HT引起的气管条收缩,其机制可能是氯离子通道阻断剂影响细胞钙运动。

Effects of chloride-channel blockers on the contraction of isolated tracheal strip of guinea pigs

AIM To study the effects and mechanisms of chloride channel blockers (NFA and NPPB) on the contraction of isolated tracheal strips of guinea pigs. METHODSThe incubated isolated tracheal strips of guinea pigs were prepared. Various drugs were added respectively. KCl or 5 HT induced contractile effects and changes in KCl or 5 HT caused by chloride channel blockers and verapamil (Ver) were determined. RESULTS The contractions induced by KCl or 5 HT in isolated tracheal strips of guinea Pig were markedly inhibited by NFA and NPPB. The depressed percentage were 100 percent and 30 percent, repectively. The inhibitory effect of Ver was intermidiate between the effects of NFA and NPPB. NFA, NPPB and Ver markedly inhibited the contractions induced by Ca 2+ released from an intracellular store and extracellular Ca 2+ . CONCLUSION NFA and NPPB can significantly inhibit contraction of tracheal strips induced by KCl and 5 HT and their mechanism may be that blocking chloride channel can affect transportation of Ca 2+ .