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

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-siteAPP-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。

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)Expressions 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.