Differential effects of pinacidil,cromakalim,and NS 1619 on electrically evoked contractions in rat vas deferens  

作　　者：黄聿[1] 刘志伟[1] 

机构地区：[1]香港中文大学医学院生理系

出　　处：《中国药理学报》1997年第4期293-298,共6页Acta Pharmacologica Sinica

摘　　要：目的：本文研究新近研制的ＡＴＰ敏感性钾通道开放剂，吡那地尔（Ｐｉｎ）和ｃｒｏｍａｋａｌｉｍ（Ｃｒｏ），以及钙离子激活性钾通道开放剂ＮＳ１６１９对电场刺激所致大鼠输精管收缩的作用．方法：利用电场刺激（０．３Ｈｚ，１ｍｓ，６０Ｖ）反复性引致输精管单相性收缩．结果：Ｐｉｎ和Ｃｒｏ浓度依赖性减低电刺激收缩．格列本脲（Ｇｌｉ）而非ｃｈａｒｙｂｄｏｔｏｘｉｎ拮抗上述两药的舒张作用．Ｐｉｎ右移去甲肾上腺素的浓度－收缩曲线，同时降低最高收缩反应．Ｇｌｉ抵消Ｐｉｎ的作用．Ｃｈａｒｙｂｄｏｔｏｘｉｎ而非Ｇｌｉ减低ＮＳ１６１９的平滑肌舒张作用．结论：ＡＴＰ敏感性和钙离子激活性钾通道参与调节输精管平滑肌的收缩性．IM: To compare the inhibitory action of electrically evoked contractions of rat epididymal vas deferens by pinacidil (Pin), cromakalim (Cro), and NS 1619. METHODS:Monophasic contractions were evoked by electric field stimulation in rat isolated epididymal half of vas deferens. RESULTS: Newly developed ATP sensitive K + channel openers, Pin and Cro, concentration dependently reduced the electrically evoked (0 3 Hz, 1 ms pulse duration, 60 V) contractions and glibenclamide but not charybdotoxin antagonized the inhibitory effects of both agents. Pin shifted the concentration response curve for norepinephrine to the right with reducing the magnitude of the maximum contraction in a glibenclamide sensitive fashion. The large conductance Ca 2+ activated K + channel opener, NS 1619, inhibited the electrically evoked contractions in a concentration dependent manner. Charybdotoxin (100 nmol·L -1 ) partially reduced the effect of NS 1619 but glibenclamide (10 μmol·L -1 ) showed no effect. None of these 3 agents affected the basal tension. CONCLUSION: Both ATP sensitive and Ca 2+ activated K + channels presented in vas deferens smooth muscles involved in regulation of muscle contractility.

关 键 词：吡那地尔 电刺激 钾通道 肌肉收缩 输精管 

分 类 号：R972[医药卫生—药品]