肺冲击伤对大鼠学习、记忆能力的影响及其机制

Effects of blast injury of the lungs on learning and memory capacity and their mechanisms in rats

目的:探讨胸部局部冲击伤后大鼠神经行为功能改变，及肺冲击伤对中枢神经系统的影响。方法:致伤前，动物均在一计算机控制的双向穿梭箱内连续训练6d，每天连续训练20次，以获得主动回避反射（AAR）。在最后2d的训练中，AAR≥80％的大鼠被选用于冲击伤实验。采用BST-Ⅲ生物激波管致大鼠单纯脑冲击伤。脑组织内NO2／NO3、cGMP含量分别采用比色测定试剂盒和酶免疫测定试剂盒进行测定。结果:①肺冲击伤后，大鼠AAR和ER明显下降.主动回避反应潜伏期（AARL）明显延长。②肺冲击伤后3、24h和5d，海马和脑子组织内NO2／NO3、cGMP含量明显升高。③海马和脑干组织内NO2／NO3水平变化分别与肺冲击伤伤情、AAR、ER和AARL值呈显著相关性。结论:单纯肺冲击伤可引起远隔器官-中枢神经系统功能损害，其机制可能与海马和脑于组织内NO释放增多有关。

Objective: To study the changes of learning and mernory capacity after blast injury of the lungs in rats. Methods: Before the infliction of blast injury, all the rats were trained in a cornputer-controlled two-way shuttle box 2O trial sessions per day for 6 consecutive days to establish active avoidance response (AAR). The rats with an acquisition rate of 80% or more for AAR in the last 2 days were inflicted with pulmonary b1ast injury (PBI) in a BST-Ⅲ bio-shock tube. Cerebral content of NO2 /NO3 and cGMP was determined with colorimetric assay kit and enzyme immunoassay kit respectively. Results: ①After PBI, AAR was significantly decreased and the latency of AAR and escape response was markedly prolonged. ②The content of NO2/NO3 and cGMP in the hippocampus and brainstem was significantly increased. ③The changes of NO2 /NO3 in the brain tissue were significantly correlated with injury severity, AAR, escape response and latency of AAR respectively. Conclusion: Our findings suggest that simple PBI can induce damages in the remote organs such as the central nervous system throuth the increased production of NO in the hippocampus and brainstern.