辣椒素对培养的大鼠三叉神经节神经元瞬时外向钾电流和延迟整流钾电流的影响  

Effects of capsaicin on I_A and I_K in cultured trigeminal ganglion neurons of rat

作　　者：傅晖[1] 刘慧[1] 曹雪红[1] 向继洲[1] 刘烈炬[1] 

机构地区：[1]华中科技大学同济医学院药理系,湖北武汉430030

出　　处：《药学学报》2004年第12期975-979,共5页Acta Pharmaceutica Sinica

基　　金：国家自然科学基金资助项目(30271500)

摘　　要：目的　探讨辣椒素(capsaicin)对大鼠三叉神经节神经元瞬时外向钾电流(IA)和延迟整流钾电流(IK)的 不同影响。方法　采用全细胞膜片钳方法。结果　对于辣椒素敏感神经元,辣椒素可选择性、剂量依赖性地抑制其 IA电流,但辣椒素对IK无明显选择性作用;对于辣椒素不敏感神经元,辣椒素对IA和IK均无作用,且对IA和IK激活动 力学亦无影响。结论　辣椒素可选择性抑制对其敏感的三叉神经节神经元IA,这可能是初次应用辣椒素时其致痛 作用的原因之一。Aim To investigate the effect of capsaicin on I A and I K in cultured rat trigeminal ganglion (TG) neurons. Methods Whole-cell patch clamp technique was used to record the I A and I K before and after capsaicin perfusion at different concentrations. Results In capsaicin-sensitive (CS) neurons,capsaicin was shown to selectively inhibit I A in dose-dependent manner,the IC 50 was 0.99 μmol·L -1. Yet capsaicin showed no inhibitory effect on I K,capsaicin (10 μmol·L -1) only slightly inhibited I K by 13.2%. In capsaicin-insensitive (CIS) neurons,capsaicin (1 μmol·L -1) showed no significant inhibitory effect on I A and I K,capsaicin (10 μmol·L -1) only slightly inhibited I A and I K by 16.8% and 15.3%,respectively. Neither 1 μmol·L -1 nor 10 μmol·L -1 capsaicin showed effect on the G-V curve of I A and I K. Conclusion Capsaicin was found to selectively inhibit the I A current in CS neurons,and this effect may contribute to hyperalgesia when capsaicin was first used.

关 键 词：辣椒素 三叉神经节神经元 瞬时外向钾电流 延迟整流钾电流 

分 类 号：R329.251[医药卫生—人体解剖和组织胚胎学] R971[医药卫生—基础医学]