吡那地尔、克罗卡林和NS 1619对大鼠输精管电诱发收缩的不同作用。

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

作者信息

Huang Y, Lau C W

机构信息

Department of Physiology, Faculty of Medicine, Chinese University of Hong Kong, Shatin, NT, Hong Kong.

出版信息

Zhongguo Yao Li Xue Bao. 1997 Jul;18(4):293-8.

PMID:10072907

Abstract

AIM

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 mumol.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.

摘要

目的

比较吡那地尔（Pin）、克罗卡林（Cro）和NS 1619对大鼠附睾输精管电诱发收缩的抑制作用。

方法

在大鼠离体附睾半侧输精管中通过电场刺激诱发单相收缩。

结果

新开发的ATP敏感性钾通道开放剂Pin和Cro浓度依赖性地降低电诱发（0.3Hz，1ms脉冲持续时间，60V）的收缩，格列本脲可拮抗二者的抑制作用，而大电导钙激活钾通道阻断剂查卡毒素无此作用。Pin使去甲肾上腺素的浓度-反应曲线右移，以格列本脲敏感的方式降低最大收缩幅度。大电导钙激活钾通道开放剂NS 1619浓度依赖性地抑制电诱发的收缩。查卡毒素（100nmol·L-1）部分减弱NS 1619的作用，但格列本脲（10μmol·L-1）无此作用。这三种药物均不影响基础张力。