缺氧及谷氨酸对大鼠下丘脑神经元NMDA通道的影响  

The roles of hypoxia and glutamic acid on NMDA receptor channel of hypothalamic neuron in rats

作　　者：陈鹏慧[1] 阮怀珍[1] 吴喜贵[1] 

机构地区：[1]第三军医大学基础医学部神经生物学教研室,重庆400038

出　　处：《第三军医大学学报》2001年第4期429-431,共3页Journal of Third Military Medical University

基　　金：国家自然科学基金资助项目! ( 396 70 2 83)

摘　　要：目的　研究缺氧和N 甲基 D 天门冬氨酸 (N methyl D asparticacid ,NMDA)通道激动剂谷氨酸对大鼠下丘脑神经元NMDA通道开放动力学的影响。方法　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通道的开放增大 ,开放时间常数τ1,τ2 分别由 (0 .3 3± 0 .10 )ms ,(4.3 6± 0 .2 6)ms变为 (0 .93± 0 .2 2 )ms ,(7.64± 0 .72 )ms ,关闭时间常数τ1,τ2 分别由 (18.0 3± 3 .5 0 )ms ,(171.5 0± 19.10 )ms变为 (3 .42± 1.0 2 )ms ,(19.3 9± 3 .0 7)ms。平均开放概率由 0 .12± 0 .0 5变为 0 .66± 0 .3 6。谷氨酸浓度增加 ,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下丘脑神经元NMDA通道的兴奋性 ,促进NMDA通道开放增加。Objective To study the effects of hypoxia and glutamic acid on the kinetic properties of NMDA receptor channel of the hypothalamic neurons in rats. Methods Cell-attached mode patch clamp technique was employed to record the single channel current of the NMDA receptor. Results The open probability of NMDA receptor channel was increased after acute hypoxia compared with that of normal state, the open time τ 1,τ 2 was changed from (0.33±0.10)ms,(4.36±0.26)ms to (0.93±0.22)ms,(7.64±0.72)ms, and the close time τ 1,τ 2 was from (18.03±3.50)ms,(171.50±19.10)ms to (3.42±1.02)ms,(19.39±3.07)ms. The mean open probability was changed from 0.12±0.05 in normal state to 0.66±0.36 in hypoxia state. Furthermore, glutamic acid can increase open time and open probability of NMDA receptor channel,decrease close time. Conclusion The excitability and the open probability of NMDA receptor channel of hypothalamic neurons increased by hypoxia is related to glutamate.

关 键 词：脑缺氧 膜 片钳技术 下丘脑神经元 NMDA受体通道 谷氨酸 大鼠 

分 类 号：R743.31[医药卫生—神经病学与精神病学]