不同浓度七氟醚对老年大鼠认知功能的影响

Effects of anesthetic sevoflurane with different concentrations on cognitive function in aged rats

摘要:

目的：观察不同浓度七氟醚麻醉对老年大鼠认知功能的影响。方法：将80只老年SD大鼠，采用数字表法随机分为5组，每组各16只。分别吸入0%（C）、1%（S1）、2%（S2）、3%（S3）、4%（S4）七氟醚6 h。用Morris水迷宫检测大鼠的认知功能，同时检测β-淀粉样物质前体蛋白（amyloid precursor protein，APP）、β淀粉样蛋白（β-amyloid peptide，Aβ）以及人BACE-1（beta-site APP-cleaving enzyme-1）的表达。结果：（1）Morris水迷宫进行定位航行实验和空间探索实验表明，S3、S4组的老年大鼠学习记忆与C组相比，潜伏期延长，穿越平台象限的次数减少（Ｆ＝１４.215，P<0.05）；而S1、S2组潜伏期及平台穿越次数差异无统计学意义（P >0.05）。（2）大鼠海马内的APP、Aβ表达都随着吸入浓度的增加而增加（P<0.05）。（3）大鼠海马中BACE-1的表达与C组相比，S3、S4组的表达显著增高（F=14.215，P<0.05）。结论：七氟醚对老年大鼠术后认知功能的影响具有剂量依赖性，而高浓度七氟醚可能通过诱导APP、Aβ生成从而引起BACE-1表达上调而发挥作用。

Abstract:

Objective：To investigate the effects of different concentrations of sevoflurane anesthesia on cognitive function in aged rats. Methods：Eighty SD rats were randomy divided into 5 groups：0% sevoflurane group（C，n=16），1% sevoflurane group（S1，n=16），2% sevoflurane group（S2，n=16），3% sevoflurane group（S3，n=16） and 4% sevoflurane group（S4，n=16）. All rats received anesthesia for 6 h. Cognitive function was tested with Morris watermaze. Amyloid precursor protein（APP），β-amyloid peptide（Aβ） and human beta-site APP-cleaving enzyme-1（BACE-1） expressions in the hippocampus were determined with ELISA. Results：（1）Morris watermaze test and spatial probe test demonstrated that both latency and the number of seeking for hidden-platform were significantly decreased in S3 and S4 groups than in control group（P<0.05），but no significant difference between S1 and S2 groups was found（P >0.05）. （2）Ex－pressions of APP and Aβ in the hippocampus were increased with increase of concentrations（P<0.05）. （3）Expressions of BACE-1 in hippocampal were significant increased in S3 and S4 groups than in control group（P<0.05）. Conclusions：Sevoflurane inhibits cognitive function of aged rats in dose-dependent manner. These results suggest high concentration sevoflurane could induce APP and Aβ and result in the up-regulation of BACE-1 expressions.