大鼠三叉神经节神经元ATP-激活电流的药理学特性  

PHARMACOLOGICAL PROPERTIES OF THE ATP-ACTIVATED CURRENTS IN THE TRIGEMINAL GANGLION NEURONS OF RAT

作　　者：张玉芹[1] 罗加烈[2] 聂辉[1] 朱凡[1] 李之望[2] 

机构地区：[1]武汉科技大学医学院生理学教研室,武汉430080 [2]华中科技大学同济医学院神经生物学系,武汉430030

出　　处：《神经解剖学杂志》2007年第1期64-68,共5页Chinese Journal of Neuroanatomy

基　　金：湖北省自然科学基金(No2004ABA152)资助项目

摘　　要：本实验应用全细胞膜片钳技术探讨了大鼠三叉神经节神经元ATP-激活电流的药理学特性。结果显示:(1)92.3%(60/65)的细胞对ATP敏感,有反应的细胞可记录到三种型式的ATP-激活电流:快速激活快速失活型(Fasttype,F型)、快速激活缓慢失活型(Intermediate type,I型)和缓慢激活缓慢失活型(Slow type,S型),三种电流均具有浓度依赖性。(2)动力学特征:三种类型的ATP激活电流上升相从10%到90%的时间:F型:33.6±4.5ms;I型:62.2±9.9ms;S型:302.1±62ms。去敏感相从10%到90%的时间:F型:399.4±58.2ms;S型:>500ms。(3)量-效关系:I型的量-效曲线居中间,F型的下移,S型的上移,三种类型电流的量-效曲线的EC50非常接近。(4)ATP受体的激动剂激活三种类型电流的效能顺序为:ATP>2-MeSATP>α,β-MeATP>UTP>ADP,其拮抗剂PPADS、RB-2和Suramin对这三种电流的拮抗作用基本相同。以上结果提示:三种型式的ATP-激活电流可能是由不同亚单位组合的P2X受体亚型所介导,不同的亚型介导的电流可能具有不同的功能。Whole-cell patch-clamp was performed to explore the Pharmacological characteristics of ATP-activated current in trigeminal ganglion （TG） neurons of rat. It was shown that： （ 1 ）The majority （92.1%, 60/65 ） of TG neurons responded to ATP applied externally with inward currents. We recorded three distinct ATP-activated currents： fast, slow and intermediate, which were concentration-dependent. （ 2 ） The time course of rising phase from 10% to 90% of the three distinct ATP-activated currents were as follows ： fast： 33.6 ±4.5 ms; intermediate： 62.2 ± 9.9 ms ; slow： 302.1 ±62 ms, and that of desensitizing phase were 399.4 ± 58.2 ms （ fast ）, and 〉 500 ms （slow）, reSpectivdy. （3）The dose-response curve for fast ATP-activated current shifted downwards as compared with the intermediate ATP-activated current, and that for the slow ATP-activated current shifted upwards. The EC50s of the three curves tend to be identical. （4） The agonists of P2 receptor were used to check the potency order of them. The result is as follows ： ATP 〉 2-MeSATP 〉 α, β-MeATP 〉 UTP 〉 ADP. The classical P2 receptor antagonists PPADS, RB-2 and Suramin markedly inhibited the three distinct ATP-activated currents, with apparently comparable potency. The results suggested that three kinds of distinct ATP-activated currents could be mediated by various subtypes of P2X receptors assembled by different subunits, and the currents could be mediated by various subtypes of P2X receptors could transmit different information.

关 键 词：ATP-激活电流 离子型ATP受体 全细胞膜片钳 三叉神经节 药理学特性 

分 类 号：R96[医药卫生—药理学]