缺氧及谷氨酸对大鼠海马神经元NMDA通道的影响  

Role of hypoxia and glutamate on NMDA receptor channel of hippocampus neuron in rats

作　　者：张敏[1] 闵羡蕙[2] 

机构地区：[1]福建省莆田学院医学院生理教研室,莆田351100 [2]南京军区解放军福州总医院95临床部

出　　处：《山西医科大学学报》2007年第11期961-964,共4页Journal of Shanxi Medical University

摘　　要：目的观察大鼠海马神经元模拟缺血缺氧时谷氨酸诱发电流的改变,研究缺氧和谷氨酸对大鼠海马神经元N-甲基-D-天门冬氨酸(N-methyl-D-asparticacid,NMDA)通道开放动力学的影响,为中枢神经损伤的康复提供理论依据。方法实验分为6组:①对照组:通氧+20μmol/LL-Glu+1.0μmol/LGly;②组1:通氧+50μmol/LL-Glu+1.0μmol/LGly;③组2:通氧+100μmol/LL-Glu+1.0μmol/LGly;④组3:通氧+200μmol/LL-Glu+1.0μmol/LGly;⑤组4:缺氧+20μmol/LL-Glu+1.0μmol/LGly;⑥组5:缺氧+20μmol/LL-Glu+1.0μmol/LGly+30μmol/LMK-801。以原代培养的大鼠海马神经元为标本,运用膜片钳技术的细胞吸附式方法记录NMDA通道的单通道电流。结果在急性缺氧条件下,NMDA通道的开放时间常数τ1,τ2较对照组延长,分别由(0.47±0.12)ms,(5.42±0.33)ms变为(1.02±0.17)ms,(7.47±0.93)ms;关闭时间常数τ1,τ2较对照组明显缩短,分别由(21.13±4.21)ms,(167.83±23.23)ms变为(6.54±1.44)ms,(21.32±2.87)ms;平均开放概率增大,由0.17±0.11变为0.79±0.32,差异有显著意义(P<0.05)。谷氨酸浓度增加时,NMDA通道开放时间常数增大,关闭时间常数减小,开放概率增大。结论缺氧及谷氨酸能提高海马神经元NMDA通道的兴奋性,促进NMDA通道开放增加。Objective To observe the changes of glutamate-induced currents in hypoxia-ischemia of hippocampus neurons in rats,and to study the effects of hypoxia and glutamate on the kinetic properties of NMDA receptor channel of the hippocampus neurons in rats so as to provide a basis for nerve rehabilitation of central nervous injury. Methods Cell-attached mode of patch clamp technique were employed to record the single channel current of NMDA receptor with the primary-cultured hippocampal neurons from rats as samples. There were 6 groups in experiment： ① control group： hyperoxia ＋ 20 μmol/L L-Glu ＋ 1. 0 μmol/L Gly; ② group 1： hyperoxia＋ 50 μmol/L L-Glu＋ 1.0 μmol/L Gly; ③ group 2：hyperoxia＋ 100 μmol/L L-Glu＋ 1.0 μmol/L Gly; ④ group 3： hyperoxia ＋ 200 μmol/L L-Glu ＋ 1.0 μmol/L Gly; ⑤ group 4 ： hypoxia ＋ 20 μmol/L L-Glu ＋ 1.0 μmol/L Gly; ⑥ group 5 ： hypoxia ＋ 20 μmol/L L-Glu ＋ 1.0 μmol/L Gly ＋ 30 μmol/L MK-801. Results The open probability of NMDA receptor channel was significantly longer in group 4 than that in control group （P〈0.05）, and the open time parameters τ1, τ2 changed from （0.47 ± 0.12） ms, （5.42 ± 0.33） ms to （1.02 ± 0.17） ms, （7.47 ± 0.93） ms; and the close time parameters τ1, τ2 were shorter in group 4 than in control group （P〈0.05）, from （21.13±4.21） ms, （167.83±23.23） ms to （6.54± 1.44） ms, （21.32±2.87） ms. The mean open probability significantly increased from 0.17 ± 0.11 to 0.79 ± 0.32 in hypoxia state （P〈 0.05）. Glutamate also increased the open time and open probability of NMDA receptor channel, and decreased close time（P 〈 0.05）. Conclusion The hypoxia and glutamate could increase excitability and open probability of NMDA receptor channel of hippocampus neurons.

关 键 词：缺氧 谷氨酸 海马神经元 NMDA受体通道 膜片钳技术 

分 类 号：R364.4[医药卫生—病理学]