急性分离大鼠新皮层神经元K_(ATP)通道特性  

Properties of ATP-sensitive potassium channels in acutely dissociated cerebral neurons of rats

作　　者：肖中举[1] 苏平[1] 高天明[1] 佟振清[1] 

机构地区：[1]第一军医大学生理教研室,广州510515

出　　处：《第一军医大学学报》1999年第5期417-420,共4页Journal of First Military Medical University

摘　　要：为研究急性分离大鼠皮层神经元上ＡＴＰ敏感钾通道的特性，本实验采用了膜片钳技术之膜内面向外记录方法。ＡＴＰ敏感钾通道电导为２００ｐＳ左右，翻转电位为０ｍＶ，有外向整流现象；通道开放常呈簇状猝发样开放，平均开放时间和开放概率随去极化程度增大而增加，随超极化程度增大而减少；低浓度ＡＴＰ有促进通道开放作用，并可激活二级电流；高浓度ＡＴＰ抑制通道开放概率并随浓度增大而增强；ＡＴＰ浓度增高到１或２ｍｍｏｌ／Ｌ时，通道电流被阻断。０.１ｍｍｏｌ／Ｌ优降糖可立即抑制通道活动。急性分离的皮层神经元上ＡＴＰ敏感钾通道特性与培养神经元有差别；低浓度ＡＴＰ可激活ＡＴＰ敏感钾通道，防止神经细胞过度兴奋，从而起到保护脑缺血缺氧损伤的作用。Properties of K_(ATP), channels in acutely dissociated cerebral neurons of rats were observed with inside-out patch-clampmethod. The channels conductance was about 200 pS, and its reversal potential was 0 mV. Outward current rectification was seenduring depolariztion. The channels opened in cluster and burst. Open time and close time were fitted with two exponents. Mean opentime and open probability increased with depolarization, but decreased with hyperpolarization. Lower ATP level enhanced openingsand activated multichannel currents. With addition of ATP, inhibition of open probability byATP was increased. The channelcurrents were blocked when the concentration of ATP in bath solution was added to 1 or 2 mmol/L or 0.1mmol/L glybenclamideapplied. There are some differences in properties of K(ATP), channels between acutely dissociated cerebral neurons neurons cultured those.Low concentration of ATP can activate K_(ATP), channel to inhibit the neural excitivity, and to protect the neurons from hypoxia andischemia damage.

关 键 词：ATP敏感钾通道 皮层神经元 脑缺血 大鼠 

分 类 号：R743.31[医药卫生—神经病学与精神病学] R338.8[医药卫生—临床医学]