远隔缺血后处理对大鼠窒息性心脏停搏复苏后脑损伤的影响

Effect of remote ischemic postconditioning on brain injury after asphyxial cardiac arrest-resuscitation in rats

目的 探讨远隔缺血后处理对大鼠窒息性心脏停搏复苏后脑损伤的影响.方法 雄性清洁级SD大鼠69只,体重300 ～ 350 g,采用完全随机法分为3组（n=23）：假手术组（S组）、窒息性心脏停搏复苏组（CA-CPR组）和远隔缺血后处理组（RIPost组）.采用窒息8 min后心肺复苏法制备模型.RIPost组于自主循环恢复后即刻对右股动脉实施3个循环的夹闭与开放,每个循环夹闭与开放均持续15 min.于自主循环恢复后24 h、72 h和7d时行神经功能评分.于自主循环恢复后48 h时采用ELISA法检测血清神经元特异性烯醇化酶（NSE）浓度.于自主循环恢复后3d采用Nissl染色法观察大鼠海马CA1区神经元的形态,并计数存活神经元.于自主循环恢复后7d进行Morris水迷宫实验.结果 与S组比较,CA-CPR组和RIPost组各时点神经功能评分和海马CA1区存活神经元计数降低,血清NSE浓度升高,逃避潜伏期延长,靶象限停留时间百分比和路程百分比降低（P＜0.05）;与CA-CPR组比较,RIPost组各时点神经功能评分和海马CA1区存活神经元计数升高,血清NSE浓度降低,逃避潜伏期缩短,靶象限停留时间百分比和路程百分比升高（P＜0.05）.RIPost组海马CA1区神经细胞损伤较CA-CPR组减轻.结论 远隔缺血后处理可减轻大鼠窒息性心脏停搏复苏后脑损伤.

Objective To investigate the effect of remote ischemic postconditioning on brain injury after asphyxial cardiac arrest-resuscitation in rats.Methods Sixty-nine male Sprague-Dawley rats were randomly divided into 3 groups （n =23 each） using a random number table：sham operation group （group S）,asphyxial cardiac arrest-resuscitation group （group CA-CPR）,and remote ischemic postconditioning group （group RIPost）.The animals were anesthetized with intraperitoneal 1％ pentobarbital 40 mg/kg,intubated and mechanically ventilated.Asphyxia was induced by occlusion of the tracheal tube and resuscitation was started 8 min later.In RIPost group,RIPost was produced by 3 cycles of 15 min occlusion of the right hind femoral artery-15 min release of the right hind femoral artery after restoration of spontaneous circulation （ROSC）.Neurological deficits were evaluated and scored at 24 h,72 h and 7 days after ROSC.Neuron specific enolase （NSE） concentration in serum was assessed at 48 h after ROSC by ELISA.At 3 days after ROSC,the number of viable neurons in hippocampal CA1 region was recorded （by N issl＇s staining）.Morris water maze test was used to quantify spatial learning and memory deficits after ROSC.Results Compared with group S,the neurological deficit score at each time point and the number of viable neurons in hippocampal CA1 region were significantly decreased,the NSE concentration in serum was increased,the escape lantency was prolonged,and the target quadrant residence time percentage and distance percentage were decreased in CA-CPR and RIPost groups.Compared with group CA-CPR,the neurological deficit score at each time point and the number of viable neurons in hippocampal CA1 region were significantly increased,the NSE concentration in serum was decreased,the escape lantency was shortoned,and the target quadrant residence time percentage and distance percentage were increased in group RIPost.The damage to neurons in hippocampal CA1 region was significantly mitigated in group RIPost as compared with group CA-CPR.Conclusion Remote ischemic postconditioning can reduce brain injury after asphyxial cardiac arrest-resuscitation in rats.