摘要
目的 观察电磁脉冲 (EMP)辐射对大鼠海马组织中N 甲基 D 天门冬氨酸 (NMDA)受体的影响 ,以深入探讨EMP致学习记忆障碍的机制。方法 EMP辐射条件为 6× 10 4V/m ,脉冲上升时间 2 0ns ,脉宽 3 0 μs ,频率 2 .5脉冲 /min ,作用 2min。二级雄性Wistar大鼠 3 2只 ,随机分为EMP组 (n =2 6)和对照组(n =6)。EMP组大鼠分别于辐射后即刻 ,3h ,6h ,2 4h和 48h断头取脑 ,剥离海马 ,制备膜受体蛋白 ,以3 H Glu为配基进行放射性配基 受体结合实验。结果 EMP辐射后即刻大鼠海马中NMDA受体的Kd值开始下降 ,辐射后 3h下降最显著 (与对照组相比 ,P <0 .0 5 ) ,6h渐有恢复 ,48h恢复至正常水平 ;受辐射的大鼠海马中NMDA受体的Bmax值于辐射后 3h和 6h显著下降 (与对照组相比 ,均P <0 .0 5 ) ,2 4h渐有恢复 ,辐射后 48hBmax值明显升高 ,超过对照组水平 (P <0 .0 5 )。结论 EMP辐射可引起大鼠海马组织中NMDA受体亲和力升高及受体密度下降。提示NMDA受体密度、亲和力的改变以及NMDA Ca2 + NO路径的兴奋毒性作用可能参与了EMP致实验动物认知障碍的分子机制。
Objective To investigate the relationship between the changes of N-methyl-D-aspartate(NMDA) receptor activity in hippocampus of rats and electromagnetic pulses(EMP) exposure. Methods Thirty-two rats were divided into a control group (6 rats) and an experimental group (26 rats),subject to EMP irradiation. The rats in the experimental group were decapitated after EMP(6×10 4V/m,rise time 20ns,pulse width 30μs,5 pulses in 2 minutes) irradiation and hippocampus were sampled,and NMDA receptor activity were detected with a radioligand binding assay with 3H-Glu. The rats in the control group were treated the same except EMP exposure. Results The Kd value of NMDA receptor decreased significantly at 3h after irradiation,then increased gradually after 6h and reached normal level at 48h after irradiation. The Bmax value of the receptor decreased significantly at 3～6h after exposure,then began to rise at 24h and reached a higher level than that of the control group. Conclusion EMP irradiation induced the decrease of both Kd and Bmax values of NMDA receptors in hippocampus of rats. It was suggested that the changes of density and affinity of NMDA receptor might be partly responsible for the cognitive deficits of rats.
出处
《中华物理医学与康复杂志》
CAS
CSCD
北大核心
2004年第7期388-391,共4页
Chinese Journal of Physical Medicine and Rehabilitation
基金
全军医药卫生指令性课题 (No.0 1L0 2 3)
