异甘草素对氯胺酮-咪达唑仑麻醉大鼠苏醒及认知功能的影响

目的研究异甘草素（ISL）对麻醉大鼠苏醒及认知功能的影响。方法 SD大鼠随机分5组,每组8只。低、中、高剂量组分别灌胃ISL 10、20、40mg/kg;正常组和模型组给等容量的溶媒。灌胃60 min后除正常组外,其他各组腹腔注射氯胺酮75mg/kg和咪达唑仑（5mg/kg）,记录大鼠翻正反射消失时间、恢复时间和共济失调期。采用Morris水迷宫测定大鼠清醒后3h的学习记忆能力。取脑海马测定超氧化物歧化酶（SOD）、谷胱甘肽（GSH）和丙二醛（MDA）水平。结果 ISL 40mg/kg组翻正反射恢复时间及共济失调期较模型组明显缩短;ISL剂量（10～40mg/kg）依赖性降低逃避潜伏期,并增加在原平台象限停留时间;ISL降低脑组织MDA含量,同时升高GSH和SOD水平。结论 ISL促进麻醉苏醒,并改善麻醉后短期认知功能,其机制与抗脂质过氧化作用有关。

Effect of Isoliquiritigenin on Recovery and Cognitive Function of Rats Receiving Ketamine-midazolam Anesthesia

Objective To study effect of isoliquiritigenin（ISL）on the recovery and cognitive function of anesthetized rats. Methods The rats were randomly divided into 5 groups： normal group,model group and three ISL-treated groups（ISL 10,20,40 mg/kg）.60 min later the rats were administered intraperitoneally with ketamine 75 mg/kg and midazolam 5 mg/kg in model group and three ISL-treated groups.The time for loss of righting reflex（LRR） and return of righting reflex,and duration of post-LRR ataxia were evaluated.The ability of learning and memory was evaluated by Morris water maze test.The levels of superoxide dismutase（SOD）,Malondialdehyde（MDA）,reduced glutathione（GSH） in hippocampus were measured. Results ISL significantly decreased time of return of righting reflex,duration of post-LRR ataxia and the escape latency,increased the duration spent in platform quadrant in a dose-dependent manner.In addition,ISL also decreased the content of MDA and increased the levels of SOD and GSH in hippocampus. Conclusion ISL could improve recovery and cognitive function of rats receiving ketamine-midazolam anesthesia and this effect is mediated by a decrease in oxidative stress and a concomitant increase in antioxidants in hippocampus.