【摘要】 目的　研究严重创伤对海马NMDA受体 (NR)活性的影响及其相关机制 ,为设法调节NR的活性从而控制创伤后HPA轴的过度兴奋提供实验依据。方法　以大鼠背部 3 0 %TBSAⅢ度烫伤作为严重创伤过度应激模型 ,利用放射配基结合法检测烫伤后海马NR活性 (最大结合容量及亲和力 )的变化 ;Western blot +免疫共沉淀方法检测烫伤海马NR1、NR2A、NR2B酪氨酸磷酸化的改变 ;高效液相色谱方法检测烫伤海马谷氨酸含量的变化。结果　严重烫伤后 0 5、1、2、4、8、2 4、48h海马NR的亲和力显著增加 ,尤以烫伤后 2h最为明显 ,最大结合量从 1h起亦显著增加 ;各时相点海马酪氨酸磷酸化NR1、磷酸化NR2A及磷酸化NR2B蛋白水平皆显著增高 ;烫伤后 0 5、1、2、4h ,海马内谷氨酸释放量增加非常明显 ,伤后 2 4h及 48h无明显变化。结论　严重烫伤导致海马NR持续过度激活 ;NR酪氨酸磷酸化水平的增加是其过度激活的重要原因 ,谷氨酸释放量的变化可能不是其持续激活的主要因素。更多还原

【Abstract】 Objective To investigate the changes of hippocampal NMDA receptor activity in rat after scald burn stress and the related mechanisms Methods Adult male Wistar rats were inflicted with 30% TBSA full thickness scalding(burn), which was applied as severe trauma stress model The hippocampal NMDA receptor activity, tyrosine phosphorylation level and hippocampal glutamate content were detected by radio ligand binding assay, immunoprecipitation + Western blot and high performance liquid chromatography methods in burn rats, respectively Results Kd value of hippocampal NMDA receptor decreased significantly in rats at 0 5, 1, 2, 4, 8, 24 h, and 48 h after burn, but the change was most significant at 2 h Receptor maximal binding capacity (B max ) was markedly elevated from 1 h to 48 h, especially at 2 h Tyrosine phosphorylated protein of NMDA receptor 1 increased markedly at 0 5, 1, 2, 4, 8, 24, 48 h after burn, and that of NMDA receptor 2A and 2B also increased in these time point burn groups Glutamate content in hippocampus increased at 0 5, 1, 2, 4 h, but decreased to normal level at 24 h and 48 h Conclusion The burn induced hyperactivation of hippocampal NMDA receptor may be resulted from enhanced tyrosine phosphorylation of NMDA receptor subunits更多还原