BTHP及吡那地尔对离体大鼠子宫平滑肌的作用

苄基四氢巴马汀（ＢＴＨＰ）及吡那地尔（Ｐｉｎａｃｉｄｉｌ）对子宫平滑肌的作用研究结果如下：ＢＴＨＰ可使子宫平滑肌的收缩频率、幅度和张力均明显增强，而Ｐｉｎａｃｉｄｉｌ不仅可抑制或取消子宫的自发性节律性收缩．表现为明显的松弛作用．而且对ＢＴＨＰ所致的子宫收缩也有明显的拮抗作用。ＢＴＨＰ能增强氯化钾及催产素所致子宫的收缩反应．使收缩幅度加大．频率加快，张力提高．而Ｐｉｎａｃｉｄｉｌ则相反．表现为明显的抑制作用．使子宫松弛。ＢＴＨＰ可使高钾去极化子宫的ＣａＣｌ２量效曲线左移、上移，而Ｐｉｎａｃｉｄｉｌ则使量效曲线右移．最大反应（Ｅｍａｘ）不变。

Effects of benzyltetrahydropalmatine and pinacidil on contractility of isolated rat uterus

Benzyltetrahydropalmatine (BTHP) is a derivative of tetrahydropalmatine and pinacidil is a novel potassium opener,The experimental results are as follows:① Spontaneous mechanical activity of rat uterus was inhibited by pinacidil and increased by BTHP.② BTHP induced contraction of rat uterus was antagonized by pinacidil.③ KCl induced isotonic.contraction of rat uterus Was suppressed by pinacidil and increased by BTHP.① A low concentration of oxytocin evoked an increase in the amplitude and frequency of rat uterus,but the tonic development increased after addition of BTHP and the markedly inhibition by pinacidil.⑤ Pinacidil shifted dose-response curve of CaCl2 to the right without change the maximal respouse in KCl-depolarized rat uterus.In contrast,BTHP produced a shift of the curve to the loft accompanied by the increase of the maximal response.