高压氧对沙土鼠脑缺血再灌注海马神经细胞NMDA受体的作用研究  

Effect of hyperbaric oxygen on the alteration of N-methal-D-aspartate in gerbils hippocampus following cerebral ischemia and reperfusion

作　　者：方以群[1] 刘景昌[1] 时粉周[1] 张明月[2] 陈海庭[1] 王瑞淦[2] 李斌[1] 张洪柱[1] 丁江舟[1] 

机构地区：[1]海军医学研究所,上海200433 [2]南京军区杭州疗养院海勤疗养区

出　　处：《中华航海医学与高气压医学杂志》2009年第4期207-210,共4页Chinese Journal of Nautical Medicine and Hyperbaric Medicine

基　　金：海军后勤部科研课题（95-3303）

摘　　要：目的探讨高压氧（HBO）作用后对缺血脑海马神经细胞N-甲基-D-门冬氨酸（NMDA）受体生物学特性的改变。方法用蒙古种沙土鼠，双侧颈总动脉结扎制作前脑缺血模型，动物随机分为假手术组、缺血再灌注组、高压氧组、氯胺酮组、氯胺酮＋高压氧组。假手术组仅分离双侧颈总动脉，不结扎颈总动脉；缺血再灌注组夹闭双侧颈总动脉30min制作全脑缺血模型，随后松开动脉夹再灌注80min；高压氧组缺血30min后打开双侧动脉夹，行0．25MPa高压氧治疗；氯胺酮组用盐酸氯胺酮麻醉，30min后夹闭双侧颈总动脉，缺血30min后松开动脉夹再灌注80min；氯胺酮＋高压氧组缺血前30min用氯胺酮腹腔注射麻醉，缺血30min后行0．25MPa高压氧治疗。采用放射配体（[^3H]-CPP）结合法测定海马神经细胞膜NMDA受体的最大结合容量Bmax和平衡解离常数Kd。结果各组Kd值有一定的改变，但差异均无统计学意义；Bmax在脑缺血时有明显改变，缺血再灌注组与假手术组相比差异有统计学意义（P〈0．01）。脑缺血后经其他几种处理的，Bmax均较缺血再灌注组明显下降（P〈0．01）。其中，氯胺酮组、氯胺酮＋高压氧组下降明显，但显著高于假手术组（P〈0．01）。结论脑缺血后，海马区神经细胞NMDA受体的Bmax显著增加，氯胺酮、氯胺酮＋高压氧治疗可使Bmax降低。可能通过此途径减少细胞外Ca^2＋内流，恢复细胞内游离Ca^2＋浓度，从而起到高压氧治疗脑缺血的作用。Objective To study the effect of hyperbaric oxygen（HBO） on the biological property of N- methal-D-aspartate （NMDA） receptor inhibitor in gerbils hippocampus following cerebral ischemia and reperfusion. Methods Mongolian gerbils were used to develop the model of hemorrhage of forebrain by ligation of bilateral arteria carotis eommunis. The animals were randomly divided into the sham surgery group, the ischemia and repeffusion group, the HBO group, the ketamine group and the ketamine plus HBO group. Radioligand （ [ ^3H]-CPP） was employed to define equilibrium binding characteristics of the NMDA receptor in hippocampus. Maximal binding （Bmax） and affinity constant （Kd） of NMDA receptors were determined. Results Changes in affinity constant （Kd） could be seen in all the groups following ischemia, but without statistical significance. Significant changes in Bmax were shown following isehemia and there was statistical importance, when a comparison was made between the ischemia and reperfusion group and the sham surgery group （P 〈 0.01 ）. Following 30 minutes of ischemia, NMDA receptor maximal binding （Bmax） of the other groups decreased more significantly than that of the ischemia-reperfusion group （P 〈 0.01 ）. Of all the groups, Bmax of the ketamine group and the ketamine plus HBO group dropped more significantly. Conclusions Results indicated that Bmax of [ ^3H ]-CPP increased markedly after 30 minutes of cerebral isehemia in gerbils hippocampns. Both ketamine and ketamine plus HBO treatment could decrease the level of Bmax, which might reduce entry of Ca^2＋ into cells during ischemia and reperfusion, and at the same time, restore concentration of intracellular calcium [ Ca^2＋ ]. All this might account for the therapeutic effect of HBO on cerebral ischemia.

关 键 词：高压氧 脑缺血 N-甲基-D-门冬氨酸(NMDA) 海马神经细胞 

分 类 号：R686[医药卫生—骨科学]