应激浓度皮质酮对大鼠海马神经元兴奋性氨基酸受体的快速作用  

Rapid effect of stressful concentration corticosterone on glutamate receptor and its subtype N-methyl-D-aspartate receptor activity in cultured hippocampal neurons

作　　者：刘玲[1] 张仁良[1] 郁文博[1] 张申宁[1] 王春安[2] 孙继虎[2] 

机构地区：[1]南京军区南京总医院神经内科,江苏南京210002 [2]第二军医大学生理学教研室,上海200433

出　　处：《医学研究生学报》2006年第5期409-413,共5页Journal of Medical Postgraduates

基　　金：国家自然科学基金资助项目(批准号:30570598)

摘　　要：目的:研究大鼠应激浓度皮质酮对兴奋性谷氨酸受体——N-甲基-D-天冬氨酸(NMDA)受体的快速调控作用及其机制。方法:运用常规膜片钳技术,研究细胞外给予应激浓度皮质酮(CORT)对原代培养的大鼠海马神经元谷氨酸(Glu)和NMDA诱发电流(IGlu和INMDA)的快速作用,以及细胞内透析CORT对INMDA影响。结果:CORT (10 μmol／L)可快速、可逆地抑制大鼠海马神经元IGlu和INMDA;细胞外牛血清清蛋白耦联的皮质酮(CORT-BSA,10 μmol／L)有与CORT相似的作用;细胞内CORT(10 μmol／L)对INMDA的峰值无明显影响。结论:提示应激浓度 CORT对大鼠巾枢神经系统兴奋性突触传递过程有快速抑制作用,对谷氨酸受体(GluR)的作用主要是通过NMDA 受体实现的;该作用是通过细胞外快速膜机制产生的。Objective：To study rapid effect of corticosterone （CORT） on N-methy-D-asparatic acid （NMDA） receptor activity in hippocampal neurons in stress and to elucidate its underlying membrane mechanisms. Methods：Whole-cell patch-clamp recording was used to assess the effect of stressful concentration on the responses of cultured hippocampal neurons to glutamate and NMDA. To make clear the target of CORT, intracellular dialysis of CORT（ 10 μmol/L）through patch pipette and extracellular application of bovine serum albumin-conjugated corticosterone（ CORT-BSA, 10 μmol/L）were carried out to observe their influence on peak amplitude of NMDA-evoked current. Results ： CORT had a rapid, reversible and inhibitory effect on peak amplitude of Glu- or NMDA-evoked currents in cultured hippocampal neurons. Furthermore, CORT-BSA had the inhibitory effect on INMDA as corticosterone; but intracellulady dialyzed CORT had no significant effect on INMDA. Conclusion ： These results suggest that under the condition of stress, CORT may rapidly, negatively regulate excitatory synaptic receptors-GluRs, especially NMDA receptor in central nervous system, which is mediated by rapid membrane mechanisms, but not by classical, genomic mechanisms.

关 键 词：应激浓度 皮质酮 N-甲基-D-天冬氨酸受体 全细胞膜片钳 

分 类 号：R338.8[医药卫生—人体生理学]