雌二醇在七氟烷诱发新生大鼠皮层癫痫样脑电波中的作用

The effect of estradiol on sevoflurane-induced epileptiform cortical EEG waves in neonatal rats

目的探讨七氟烷麻醉诱发新生大鼠皮层癫痫样脑电波机制是否和神经活性甾体雌二醇有关。方法新生SD大鼠40只,4~6日龄,体质量8~15 g,采用随机数字表法分为5组(n=8):生理盐水对照组(C组)、雌二醇组(E组)、ICI182780(I组)、福美司坦组(O组)、雌二醇+ICI182780(EI组)。建立新生大鼠皮层脑电图监测模型后,持续记录脑电图30 min,然后按照分组不同分别给予不同的处理药物,再持续记录脑电图30 min后开始吸入6%七氟烷3 min行麻醉诱导,随后吸入2.1%七氟烷维持麻醉,七氟烷麻醉时间共1 h。记录七氟烷麻醉后动物翻正反射消失时间;记录脑电图出现惊厥波的总持续时间、单次持续时间及次数;记录不同时间段棘波频率。七氟烷麻醉诱导后记录动物呼吸频率。结果I组和EI组各有一例动物在注射处理药物前出现惊厥波,从本研究剔除。S组、E组、I组、O组和EI组的翻正反射时间分别为(24.4±2.5)s、(16.4±4.2)s、(31.8±5.2)s、(29.8±1.8)s、(24.8±2.7)s,组间比较差异有统计学意义(F=16.693,P<0.01)。各组麻醉中呼吸频率比较差异无统计学意义(F=0.276,P>0.05)。与S组相比,E组在麻醉期间的惊厥波总持续时间、单次持续时间及发作次数明显增加,均差异有统计学意义(P<0.05);与E组及S组比较,I组、O组、EI组麻醉期间的惊厥波总持续时间、单次持续时间及发作次数明显减少,差异有统计学意义(P<0.05)。与S组相比,E组在各时间段内棘波频率明显增加,差异有统计学意义(P<0.05);I组、O组及EI组在65~70 min及90~95 min棘波的频率低于S组,差异有统计学意义(P<0.05);O组及EI组在115~120 min时与S组及E组比较棘波的频率差异有统计学意义(P<0.05)。结论七氟烷麻醉期间引起癫痫样脑电波的机制与神经活性甾体雌二醇有关。

Objective To investigate the effect of estradiol on sevoflurane-induced epileptiform cortical EEG waves in neonatal rats.Methods Forty neonatal rats,aged 4-6 days,weighting 8-15 g,were divided into 5 groups according to random number table:normal saline control group(group C),estradiol group(group E),ICI182780(group I),Formestane group(group O)and estradiol+ICI182780(group EI).After establishing the monitoring model of cortical electroencephalogram in neonatal rats,EEG was recorded continuously for 30 minutes,then different treatment drugs were given according to different groups.After 30 minutes of continuous recording of EEG,anesthesia induction was started with inhalation of 6%sevoflurane for 3 minutes,followed by inhalation of 2.1%sevoflurane to maintain anesthesia.Sevoflurane anesthesia lasted for 1 hour.The righting reflex disappearance time was recorded after sevoflurane anesthesia.The total duration,single duration and frequency of EEG convulsion waves were recorded.Spike frequencies were recorded at different periods.Animal respiratory rate was recorded after sevoflurane induction.Results One rat in group I and one rat in group EI showed convulsion wave before treatment,which were excluded from the study.The righting reflex disappearance time of group S,group E,group I,group O and group EI were(24.4±2.5)s,(16.4±4.2)s,(31.8±5.2)s,(29.8±1.8)s,(24.8±2.7)s respectively,and there were statistically significant differences among the 5 groups(F=16.693,P<0.01).There were no significant difference in respiratory frequency among the 5 groups(F=0.276,P>0.05).Compared with group S,the total duration,single duration and frequency of convulsion wave were significantly increased in group E during anesthesia,and the differences were statistically significant(P<0.05).Compared with group E and group S,the total duration,single duration and frequency of convulsion wave during anesthesia were significantly reduced in group I,group O and group EI,and the differences were statistically significant(P<0.05).Compared with group S,the spike frequency of group E increased significantly in each period,and the differences were statistically significant(P<0.05).The frequency of spike wave in group I,group O and group EI at 65-70 min and 90-95 min were lower than that in group S,and the differences were statistically significant(P<0.05).The frequency of spike wave between group O and group EI during 115-120 min was statistically different with group S and group E(P<0.05).Conclusion The mechanism of epileptiform EEG wave induced by sevoflurane anesthesia may be related with neuroactive steroidal estradiol.