严重烫伤后大鼠海马NMDA受体通道特性的变化

目的 研究严重创伤对海马NMDA受体功能的影响，为控制创伤后的过度应激反应提供实验依据。方法 以大鼠背部30％TBSAⅢ度烫伤作为严重创伤过度应激模型，利用细胞贴附式膜片钳技术，观察严重烫伤后0.1,1,2,4,8,24,48h海马NMDA受体单通道电流的变化。结果 在35pS电导水平的开放中，各烫伤组海马NMDA受体的电流幅度与对照组相比无显著差异，但开放概率增加非学显著，烫伤后0.1,1,2,4,8h组开放时间常数τ1和τ2均比对照组显著增加，各烫伤组关闭时间无明显变化。在100pS电导水平和开放中，各烫伤组电流幅度与对照组相比无显著改变，但通道开放概率增加非常显著。2h烫伤组开放时间常数τ1和τ2也比对照组显著增加，通道的关闭时间无明显差异。结论 严重烫伤主要引起海马NMDA受体通道开放概率显著增加，导致NMDA受体通道显著激活。

Changes of kinetic properties of hippocampal NMDA receptor in rats after severe scald burn

Objective To investigate the changes of kinetic properties of hippocampal NMDA receptor in rat following scald burn stress. Methods Adult male Wistar rats were inflicted with 30% TBSA full thickness scalding, which was applied as severe trauma stress model. Kinetic properties of hippocampal NMDA receptor channel were detected by cell attached patch clamp technique. Results Open state probability of 35pS and 100 pS NMDA receptor channels increased markedly at 0.5 h, 1 h, 2 h, 4 h, 8 h, 24 h, and 48 h after burn. Significant change was found at 2 h. Open time of these channels also increased in some burn groups. No significant changes of NMDA receptor current amplitude and close time were found in each burn group. Conclusion Scald burn induces significant changes of kinetic properties of hippocampal NMDA receptor, resulting in hyperactivation of hippocampal NMDA receptor.