全身麻醉对大鼠学习记忆能力及脑额叶、海马和杏仁核半胱氨酸蛋白酶-3基因表达的影响

Effects of general anesthesia on learning and memory ability and Caspase-3 gene expression in frontal lobe,hippocampus and amygdale of rats

目的:探究全身麻醉对大鼠学习记忆能力及脑额叶、海马、杏仁核半胱氨酸蛋白酶-3(Caspase-3)基因表达的影响。方法:选用80只SD大鼠随机分为四组,每组20只。分别为对照组(不作处理)、低剂量组(1.0 mg/kg氯胺酮诱导复合2 mg/kg丙泊酚)、中剂量组(1.5 mg/kg氯胺酮诱导复合2 mg/kg丙泊酚)、高剂量组(2.0 mg/kg氯胺酮诱导复合2 mg/kg丙泊酚)。麻醉处理第1天后各组断头10只,剩余10只于麻醉前、麻醉后第1、2、3天分别进行Morris水迷宫测试,并于第1天使用TUNEL法和Western blot法检测神经细胞凋亡水平和Caspase-3蛋白表达情况。各组大鼠分别于处理后0.5、1、2 h使用荧光定量PCR(RT-PCR)法检测脑额叶、海马和杏仁核Caspase-3基因mRNA水平。结果:对照组术后第1、2、3天逃避潜伏期及平台有效期逗留时间比较,差异均无统计学意义(均P>0.05);与对照组相比,低剂量组、中剂量组可见麻醉后逃避潜伏期、翻转空间有效逗留区时间少量增加(均P>0.05),高剂量组明显增加(均P<0.05);低、中剂量组第2、3天逃避潜伏期、翻转空间有效逗留区时间与术后第1天比较均无统计学差异(均P>0.05),高剂量组明显缩短(均P<0.05)。高剂量组细胞凋亡率较对照组、低剂量组、中剂量组均显著升高(均P<0.05)。高剂量组Caspase-3蛋白表达量、Caspase-3基因mRNA水平较对照组、低剂量组、中剂量组均明显升高(均P<0.05)。结论:高浓度的全身麻醉对脑额叶、海马、杏仁核Caspase-3基因表达有一定影响,但影响时间较短,可为临床上选择麻醉药物提供一定依据。

Objective:To explore the effects of general anesthesia on learning and memory ability and gene expression in frontal lobe,hippocampus and amygdala of rats.Methods:A total of 80 SD rats were randomly divided into control group(no treatment),low-dose group(1.0 mg/kg ketamine combined with 2 mg/kg propofol),medium dose group(1.5 mg/kg ketamine combined with 2 mg/kg propofol),and high-dose group(2.0 mg/kg ketamine combined with 2 mg/kg propofol),with 20 rats in each group.10 rats in each group were decapitated on the first day of anesthesia.Morris water maze test was performed on the remaining 10 rats before anesthesia and on the 1,2 and 3 days after anesthesia.TUNEL and Western blot were used to detect the apoptosis level and Caspase-3 protein expression on the first day.The mRNA levels of Caspase-3 in frontal lobe,hippocampus and amygdala were detected by RT-PCR at 0.5,1 and 2 hours after treatment.Results:There was no significant difference in escape latency and effective stay time of platform in the control group among 1,2 and 3 days after operation(all P>0.05).Compared with the control group,the escape latency and effective stay time of flipped space in low-dose group and medium dose group were slightly increased(all P>0.05),while those in high-dose group were significantly increased(all P<0.05).The escape latency and effective staying time of flipped space in low-dose group and medium dose group on the 2 and 3 days were not significantly different from those on the first day(all P>0.05),while those in high-dose group were significantly shorter(all P<0.05).The apoptosis rate of high-dose group was significantly higher than that of control group,low-dose group and medium dose group(all P<0.05).Caspase-3 protein expression and Caspase-3 gene mRNA level in high-dose group were significantly higher than those in control group,low-dose group and medium dose group(all P<0.05).Conclusion:High concentration of general anesthesia has a certain effect on the expression of Caspase-3 gene in frontal lobe,hippocampus and amygdala,but the effect time is short,which can provide certain basis for clinical selection of anesthetic drugs.