缺氧预处理对脑缺血大鼠脑电图的影响

Effect of hypoxic preconditioning on electroencephalogram in brain ischemic rats

目的:观察缺氧预处理后脑缺血大鼠的脑电图(EEG)变化,探讨脑电活动改变在脑缺血耐受中的作用。方法:60只雄性Wistar大鼠被随机分为3组:①窒息心停跳组(ACA组,n=20),大鼠遭受窒息性心跳停止,1min后复苏;②缺氧预处理+窒息心停跳组(HP+ACA组,n=20),在窒息性心停跳前24h预先给予大鼠1min的缺氧预处理4次,每次间隔5min;③缺氧预处理组(HP组,n=20),只给予4次缺氧预处理。观察各组大鼠窒息后心跳停止时间(TCA)、开始复苏后自主循环恢复时间(TROSC)、死亡率和复苏后神经功能评分(NDS),记录预处理及缺血期间EEG变化。结果:ACA组和HP+ACA组大鼠死亡率分别为30%和5%(P<0.01);与ACA组比较,HP+ACA组TCA明显延长而TROSC明显缩短(P<0.01),复苏后24、48和72h的NDS明显改善(P<0.01),窒息后EEG等电位时间、复苏后EEG出现时间和连续EEG出现时间均明显缩短(P<0.05)。结论:缺氧预处理可通过调整大鼠脑电活动诱发脑缺血耐受作用。

Objective To observe the electroencephalogram（EEG）changes of asphyxial cardiac arrest（ACA）after hypoxic preconditioning（HP）in rats and investigate the activity of EEG in brain ischemic tolerance.Methods Sixty male Wistar rats were randomly assigned to three groups：①ACA group（n=20）,the rats were subjected to 1 min of ACA and then resuscitated;② HP＋ACA group（n=20）,the rats were pretreated with 4 times of 1 min HP 24 h before ACA;③HP group（n=20）,the rats were treated with 4 times of 1 min HP.The mortality,EEG,time from initiation of asphyxia to CA（TCA）and time from resuscitation to restoration of spontaneous circulation（TROSC）were recorded;neuro-functional outcome was assessed by neurodeficit score（NDS）.Results The mortality was 5% in HP＋ACA group and 30% in ACA group（P〈0.01）;compared with ACA group,the rats in HP＋ACA group showed much shorter TCA and significant longer TROSC（P〈0.01）.NDS in HP＋ACA group was greatly better than in ACA group（P〈0.01）;the time to EEG silence and restoration of EEG were significantly shorter in HP＋ACA group（P〈0.05）.Conclusion Hypoxic preconditioning can induce brain ischemic tolerance through EEG activity modulation.