pHi对急性分离大鼠新皮层神经元KATP通道的影响  

THE EFFECTS OF INTRACELLULAR pH i ON 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：《中国应用生理学杂志》2000年第1期1-5,共5页Chinese Journal of Applied Physiology

基　　金：国家自然科学基金!( 3 95 70 2 63 );广东省自然科学基金!( 95 0 5 3 7)资助项目

摘　　要：目的和方法 :采用膜片钳技术之膜内面向外记录方法 ,在急性分离大鼠皮层神经元上 ,研究胞内酸碱环境改变对神经元ATP敏感钾通道的影响。结果 :Vp =+6 0mV时 ,pH6 .0组开放概率 2 .2 0 %± 0 .5 7% (n =1 0 )较 pH7.3时的开放概率 8.41 %± 1 .2 0 % (n =1 6 )显著降低 (P <0 .0 1 ) ;pH 8.0组开放概率 1 8.2 9%± 4.0 5 % (n =8)较 pH7.3时明显增加 (P <0 .0 1 )。当浴液由 pH 7.3降为pH 6 .0时 ,有 40 %出现多级通道电流并可逆转。当浴液 pH6 .0及 pH 8.0时 ,ATP抑制通道开放概率的量效曲线 ,与pH 7.3时比较无明显改变 (P >0 .0 5 )。 结论 :脑细胞内氢离子可能参与KATP通道的调节 :胞内酸化环境可进一步激活KATP通道多级电流 ,保护脑缺血缺氧损伤 ;而KATP,通道开放 ,膜超极化到一定程度 ,胞内酸化环境又可抑制通道开放。Aim and Methods: Using inside out configuration of patch clamp technique, the effects of intracellular pH on K ATP channels were studied in acutely dissociated cerebral neurons of rats. Results: The probability of group pH 6.0 (2.20%±0.57%, n =10) was lower than pH 7.3(8.41%±1.2%, n =16, P <0.01), and that of group pH 8.0 (18.29%±4.05%, n =8) higher than pH 7.3( P <0.01) as the membrane potential held at hyperpolarization (+60 mV). Lowing pH of bath solution from 7.3 to 6.0, multichannel currents were seen at 40%. After reversing, that could recover to its original level. The inhibitory effect of ATP on channel open probabilities at pH 6.0 or 8.0 didn't change obviously from pH 7.3( P >0.05). Conclution: Intracellular H + could probably take part in regulating K ATP channel by activating multi channel currents of K ATP channel or by inhibiting exceed activity of K ATP channel.

关 键 词：PHI ATP敏感钾通道 皮层神经元 脑缺血缺氧 保护 

分 类 号：Q424[生物学—神经生物学] R338.8[生物学—生理学]