丙泊酚麻醉对老龄大鼠认知功能和海马蛋白质组的影响

Effects of post-propofol anesthesia on cognitive function and hippocampus proteome expressions in aged rats

目的观察丙泊酚麻醉对老龄大鼠认知功能和海马蛋白质组表达的影响。方法选取无认知功能障碍的雄性Wistar大鼠30只，20月龄，数字抽签随机分为对照组和丙泊酚组各15只。对照组腹腔注射生理盐水（6ml／kg），丙泊酚组腹腔注射丙泊酚（60mg／kg）。两组分别于麻醉结束后第1天和第7天行跳台实验测定认知功能；分别于第1次和第2次跳台实验结束后随机抽取5只大鼠，取其海马行圾向凝胶电泳和质谱分析。结果与对照组比较，丙泊酚组大鼠麻醉后第1天学习能力减邀，具体表现为：丙泊酚组学习潜伏期延长[（19．7±7．0）s比（29．5±7．6）s]，学习错误次数增多[（1．6±0．8）次比（3．6±1．2）次]，学习期受电击总时间延长[（42．7±10．3）S比（65．2±10．6）s]（均P〈0．01）；记忆潜伏期缩短[（111．2±23．7）s比（31．4±14．3）s]（P〈0．01）。而麻醉后第7天，两组各项指标比较，差异无统计学意义。丙泊酚麻醉后第1天差异表达的蛋白质17个，其中6个蛋白质表达上渊，11个蛋白质表达下调（P〈0．05）；第7天时，差异表达的蛋白质有10个，其中5个蛋白质表达上调，5个蛋白质表达下调（P〈0．01）。结论老龄大鼠接受丙泊酚麻醉后认知功能下降，但不会造成长期影响，其机制可能与海马蛋白质的差异表达有关。

Objective To investigate the effects of post propofol anesthesia on cognitive function and bippocampus proteome expressions in aged rats. Methods Thirty healthy male Wistar rats aged 20 months were randomly divided into control group（n=15）and propofol group（n= 15）. The control group was injected with normal saline of 6 ml/kg intraperitoneally and propofol was injected intraperitoneally with propofol 60 mg/kg. The rats in both groups underwent Step-down Test to assess cognitive function at the first day and at the seventb clay after the termination of drug administration. Five rats were decapitated randomly each time after tbe two step-down tests and their hippocampi were removed for two-dimensional gel electrophoresis and mass spectrometric analysis. Results In the step-down test, aged rats in the propofol group showed significantly learning impairment and decreased memory abilities at the 1st day after propofol anesthesia as compared with those in the control group. In learning phase of the 1st day, the latency of the propofol group is （29.5±7.6）s as compared with（19.7±7.0）s of the control group,while the error time is 3.6±1.2 vs. 1.6±0.8 in the propofol group vs the control group, and the total time of electric shock is（65.2± 10.6）s vs. （42.7±10.3）s in the propofol group vs the control group（all P〈0.01）. The latency of the memory phase in the propofol group is also decreased as compared with that in the control group（31.4±14.3）s vs. （111.2±23.7） s, （P〈0.01 ）. On the 7th day after anesthesia, there was no significant difference between the two groups. There were 17 differentially expressed proteins on the 1st day after propofol anesthesia, 6 of them were up-regulated and 11 proteins were down regulated （P〈0.05） . On the 7th day, there were 10 differentially expressed proteins, and the expression of 5 proteins was down regulated （P〈0.01）. Conclusions Aging rats receiving propofol anesthesia show cognitive function decline, but do not show a long-term decline. The mechanism may be related to the different expressions of hippocampal proteins.