中国临床康复2004，Vol.8Issue(31)：7029-7031,3.
缺血损伤对神经元膜表面AMPA受体构成变化的影响
Effect of ischemic injury on constitutional change of AMPA receptors of neuron membrane
摘要
Abstract
BACKGROUND:The over activation of α-amino-3-hydroxy -5methylisoxazole-4-propionic acid(AMPA) receptor plays an important role in the occurrence of brain secondary damage. Recent studies showed that the decrease of the second unit of AMPA receptor(GluR2) mainly induced Ca2 +fast influx.However,how the membrane AMPA quantity and constitution (constructiveratio of subunits) changes after ischemic injury were not clarified.OBJECTIVE:To probe into the changes of the subunits(GluRs) content,constitution of AMPA receptor on neuron membrane involving in ischemia,and furthermore to elucidatethe contribution of these changes to the Ca2 +influx and the death of neuron so as to provide the theoretical basis for the intervention way of highly specific drugs for ischemia.DESIGN: A randomized and controlled experiment was conducted.SETTING: Research institute of field surgery, daping hospital, third military medical university MATERIALS: Eighteen SD rats at gestation for 18 days were provided by animal center of research institute of surgery, and the hippocampal cells were separated from embryos and cultured.INTERVENTIONS: Neuron in the ischemic injury group was put into a specific box for anoxic challenge 30 minutes after replacement of culture medium with glucose free extracellular solution, and then re-cultured after adding culture medium. Neuron in the control group underwent the same medium replacement of normal medium at the same time. The quantities of GluRs on the neuron membrane were quantitatively measured with colorimetric assay and double immuno-fluorescence labeling on neuron anoxic model. The death of neuron was quantitated with PI staining. Intracellular Ca2 + content was determined with Fura-2 method.MAIN OUTCOME MEASURES: ① The number of the dead cells after injury. ② The quantities of GluRs on the neuron membrane and synapse. ③ lntracellular Ca2 + concentration. RESULTS: The constitutional ratio of GluR2 positive staining synapses at 24hours after ischemic injury was 0. 42 ±0. 16, which was significantly lower than that of the control group(0. 58 ± 0.15,t = 2.348,P=0.023).The membrane GluR2 also marked and decreased compared with the control group( t = 2.427, P = 0.019).The GluR3 positive synapses and membrane content, however, increased significantly. The ratio of membrane GluR3 at 24hours to preinjury was 1.23 ± 0. 23, which was statistically different from that in the control group( t = 2.114,P = 0.040).The membrane GluR1 also showed an increasing trend. Intracellular Ca2 + concentration in the injury group was 1.36 times higher than that in the control group(t = 2. 571, P =0.017).The amount of dead neuron in the ischemic injury group was significantly higher that in the control group ( t = 4. 083, P = 0.000 1 ).CONCLUSION: Ischemic injury will induce the constitution changes of AMPA receptors on neuron membrane. The reduction of membrane GluR2and the increase in GluR3 and GluR1 will accelerate Ca2+ influx and the death of neuron,which plays an important role in the occurrence of secondary cerebral damage.关键词
缺血/AMPA受体/钙离子分类
医药卫生引用本文复制引用
刘宝松,陈恒胜,许忠,陈力学,曾琳,龙在云..缺血损伤对神经元膜表面AMPA受体构成变化的影响[J].中国临床康复,2004,8(31):7029-7031,3.基金项目
重庆市科技计划项目(8107)资助 （8107）
