多次七氟醚麻醉对新生大鼠海马ApoE表达的影响

Effects of multiple exposures to sevoflurane anesthesia on expression of apolipoprotein E in hippocampus of neonatal rats

目的评价多次七氟醚麻醉对新生大鼠海马载脂蛋白E（ApoE）表达的影响。方法清洁级健康SD大鼠24只，7日龄，雌雄各半，体重15—20g。采用随机数字表法分为2组（n=12）：对照组（Con组）和多次七氟醚麻醉组（Sev组）。Sev组于出生后7、14和21d时吸入2．6％七氟醚2h，Con组吸入空氧混合气体。于出生后31～37d行Morris水迷宫实验测定认知功能，随后处死大鼠取海马，采用免疫组化法检测ApoE表达；实时荧光定量PCR法检测ApoEmRNA表达。结果2组大鼠认知功能比较差异无统计学意义（P〉0．05）。与Con组比较，Sev组海马CAl区和CA3区ApoE表达、海马ApoEmRNA表达上调（P〈0．05），DG区ApoE表达差异无统计学意义（P〉0．05）。结论多次七氟醚麻醉可上调新生大鼠海马ApoE表达，产生轻度神经毒性，但未引起认知功能变化。

Objective To evaluate the effects of multiple exposures to sevoflurane anesthesia on the expression of apolipoprotein E （ApoE） in the hippocampus of neonatal rats. Methods Twenty-four patho- gen-free Sprague-Dawley rats （ 12 males, 12 females） , aged 7 days, weighing 15-20 g, were randomly divided into 2 groups （n = 12 each） using a random number table： control group （group Con） and muhiple exposures to sevoflurane anesthesia group （group Sev）. On postnatal day 7, 14 and 21, 2. 6% sevoflurane was inhaled for 2 h in group Sev, while the mixed gas of oxygen and air was inhaled instead of sevofiurane in group Con. Morris water maze test was carried out on postnatal day 31-37 to assess cognitive function. The rats were then sacrificed, and the hippocampus was removed to determine the expression of ApoE protein in hippocampal CA1, CA3 and DG regions （by immunohistochemistry） and the expression of ApoE mRNA （by fluorescent quantitative real-time reverse transcriptase polymerase chain reaction）. Re- sults There was no significant difference between the two groups in cognitive function （P〉0.05）. Com- pared with group Con, the expression of ApoE protein in hippocampal CA1 and CA3 regions and ApoE mRNA was significantly up-regulated in group Sev （P〈0.05） , and no statistically significant change was found in the expression of ApoE protein in hippoeampal DG region in group Sev （P〉0.05）. Conclusion Multiple exposures to sevoflurane anesthesia can up-regulate the expression of hippocampal ApoE and produce mild neurotoxicity without causing changes in cognitive function in neonatal rats.