卡托普利增强豚鼠气道C神经纤维兴奋所致的收缩反应

Captopril increases the contractions of guinea pig airway induced by the activation of the nervous C fibers in vitro

目的：研究卡托普利对气道感觉神经末梢兴奋所致反应的影响，间接了解卡托普利是否具有抑制神经激肽降解作用。方法：采用电场透壁刺激法或低浓度辣椒素刺激法，引起豚鼠离体气道标本的感觉神经末梢兴奋释放神经激肽。结果：卡托普利（３、１０μｍｏｌ·Ｌ－１）和中性内肽酶抑制剂ｔｈｉｏｒｐｈａｎ的作用相似，能增强气管、支气管感觉神经末梢兴奋引起的平滑肌收缩反应。结论：卡托普利可能有抑制气道神经激肽的降解作用。

AIM:We want to know whether captopril inhibits the activity of neutral endopeptidase (NEP) in airway and increases bronchoconstriction. METHODS:The sensory nervous C fibers of airway in guinea pig could be activated by electrical field stimulation (EFS) or low concentration of capsaicin in vitro , which induce contractions of smooth muscle. Pretreatments with thiorphan and captopril could affect the contractions of airway. RESULTS:The inhibitor of neutral endopeptidase, thiorphan 10 μmol·L -1 , increased the contraction tension of the airway induced by the activation of C fibers. The actions of captopril(3, 10 μmol·L -1 ) are similar to one of thiorphan. Treatments with captopril 10 μmol·L -1 increased tracheal and bronchial contractions by EFS from 16 4±15 4 and 43 7±28 4 to 37 8±20 8 and 58 7±40 1 mg, respectively ( P <0 05). Treatments with captopril increased the tracheal contractions by the low concentration of capsaicin, from 13 3±2 3 to 34 7±9 87 mg ( P <0 01). CONCLUSIONS:These results show that captopril may inhibit the degradation of the neurokinins, inducing the enlargement of contraction tension of airway smooth muscles in guinea pig.