大鼠海马神经元Na^+ Ca^(2+)交换电流在低氧时的变化  

THE CHANGES OF Na^+ Ca^(2+) EXCHANGE CURRENT IN HIPPOCAMPAL NEURONS DURING HYPOXIA

作　　者：单红蕖[1] 郑平[1] 程介士[1] 

机构地区：[1]上海医科大学医学神经生物学国家重点实验室,上海200032

出　　处：《中国应用生理学杂志》1999年第4期298-300,共3页Chinese Journal of Applied Physiology

基　　金：国家自然科学基金

摘　　要：目的：探讨在低氧性脑损伤发生过程中，Ｎａ＋Ｃａ２＋ 交换体在细胞内钙超载中的作用。方法：采用全细胞膜片钳方法，在急性分离海马神经元上观察低氧对Ｎａ＋Ｃａ２＋ 交换电流的电流电压（ＩＶ） 曲线的影响。结果：在整个膜电位水平，Ｎａ＋Ｃａ２＋ 交换电流幅值均不同程度的增加，在正膜电位水平呈现一显著的外向电流。１０ ｍＶ 时，电流幅值从（９２ ．８３ ±２０．８）ｐＡ上升到（１３０ ．６７ ±２６．８８）ｐＡ（ Ｐ＜０ ．０５） ，而在５０ ｍ Ｖ，其电流幅值从（－ ７４ ．６７ ±１１ ．８４）ｐＡ上升到（－ ５８ ．５±１０ ．７１）ｐＡ（Ｐ＜ ０ ．０５）。结论：低氧时Ｎａ＋Ｃａ２＋ 交换电流呈外向性，这种改变有利于低氧后通过Ｎａ＋Ｃａ２＋ 交换的外向转运方式排出细胞内钠。Aim: To study the role of Na + Ca 2+ exchanger on intracellular calcium overload during hypoxia. Methods: Using whole cell patch clamp method, we observed the effect of hypoxia on the I V curve of Na + Ca 2+ exchange current in hippocampal neurons. Results: At all membrane potential levels, the amplitude of Na + Ca 2+ exchange current increased. The amplitude of the current elevated from (92.83±20.8)pA to (130.67±26.88) at 10 mV ( n =6, P <0.05) and from (-74.67±11.84)pA to (-58.5± 10.71 )pA at -50 mV( n =6, P <0.05). Conclusion: Na + Ca 2+ exchange current was possesed of outward speciality during hypoxia. These changes promote the outflow of intracellular sodium and the inflow of calcium for exchange. Methods: Using whole cell patch clamp method, we observed the effect of hypoxia on the I V curve of Na + Ca 2+ exchange current in hippocampal neurons. Results: At all membrane potential levels, the amplitude of Na + Ca 2+ exchange current increased. The amplitude of the current elevated from (92.83±20.8)pA to (130.67±26.88) at 10 mV ( n =6, P <0.05) and from (-74.67±11.84)pA to (-58.5± 10.71 )pA at -50 mV( n =6, P <0.05). Conclusion: Na + Ca 2+ exchange current was possesed of outward speciality during hypoxia. These changes promote the outflow of intracellular sodium and the inflow of calcium for exchange. Using whole cell patch clamp method, we observed the effect of hypoxia on the I V curve of Na + Ca 2+ exchange current in hippocampal neurons. Results: At all membrane potential levels, the amplitude of Na + Ca 2+ exchange current increased. The amplitude of the current elevated from (92.83±20.8)pA to (130.67±26.88) at 10 mV ( n =6, P <0.05) and from (-74.67±11.84)pA to (-58.5± 10.71 )pA at -50 mV( n =6, P <0.05). Conclusion: Na + Ca 2+ exchange current was possesed of outward speciality during hypoxia. These changes promote the outflow of intracellular sodium and the inflow of calcium for e

关 键 词：低氧 海马 神经元 钠钙交换 脑缺氧 脑缺血 

分 类 号：R743.310.2[医药卫生—神经病学与精神病学] R364.4[医药卫生—临床医学]