七氟醚麻醉对新生鼠学习与记忆的影响

目的 探索用七氟醚麻醉发育期小鼠是否会引起成长过程中学习记忆障碍。 方法 实验包括122只新生鼠(出生后7 d)。其中72只分别经七氟醚1.0或0.5最低肺泡有效浓度(minimum alveolar concentration,MAC)麻醉或吸入40% O₂ 2 h,4周或12周行水迷宫实验,记录训练各天潜伏期和游泳速度,以及探索期平台滞留时间和平台穿越次数。另外50只小鼠用于测定七氟醚麻醉(1.0或0.5 MAC)过程(0、1、2 h)中动脉血血气分析。 结果 新生鼠在整个麻醉过程中,pH值、PaCO₂、PaO₂和SaO₂均保持稳定,P>0.05。麻醉后4周,训练期后3 d,对照组小鼠潜伏期明显低于麻醉组,且后2 d,0.5 MAC组小鼠的潜伏期明显短于1.0 MAC组。探索期,对照组小鼠平台停留时间和平台穿越次数均明显高于2组麻醉组。麻醉后12周,1.0 MAC组小鼠在训练第5天潜伏期仍明显延长。探索期,对照组小鼠平台停留时间和(或)平台穿越次数均明显高于麻醉组。 结论 七氟醚麻醉引起新生鼠成长过程中学习与记忆障碍,其程度与药物浓度有关,且随时间推移减弱。

The effects of sevofluraneon learning and memory of neonatal mice

Objective To evaluate the effects of sevoflurane on learning and memory of neonatal mice. Methods 122 neonatalmice (7 days postnatal) were included in this study.72 of them were exposed to sevoflurane (1.0 or 0.5MAC,minimum alveolar concentration) or 40% O₂ for 2 h(hours). Morris water maze was performed 4 and 12 weeks after anesthesia. Latency and swimming speed during training, time on island and times across island during the research were recorded. The rest 50 mice was used in artery blood analysis during sevoflurane (1.0 or 0.5 MAC, 0,1,2 h). Results pH,PaO₂, PaCO₂, SaO₂ were stable during anesthesia. Latency in control group were significantly shorter than the two anesthesia groups 4 weeks after anesthesia and 3 days after the training. During the last 2 training days, the latency in 1.0 MAC sevoflurane-exposed mice were significantly longer than that of the 0.5 MAC group.12 weeks after anesthesia, the latency was still significantly longer in 1.0 MAC sevoflurane-exposed mice on the last training day. The time on island and/or times across island were significantly decreased in anesthesia groupsduring theresearch performed 4 weeks and 12 weeks after anesthesia. Conclusion Early exposure to sevoflurane leads to a concentration and time-depended persistent learning and memory deficits to neonatal mice.