异氟烷对血管性痴呆老年大鼠学习记忆的影响

目的研究不同浓度异氟烷麻醉后对血管性痴呆（vascular dementia，VaD）老年大鼠学习记忆的影响。方法采用四血管法（4-VO）制作VaD老年大鼠模型，60只SD老年大鼠，雌雄各半。根据模型大鼠吸入异氟烷后开始实验的天数（1天和7天）和吸入浓度（0、1．5％、2．0％）分为6组，即：1天未吸入异氟烷组（Ⅰ1,0），1天1．5％异氟烷组（Ⅰ1,1.5%），1天2％异氟烷组（Ⅰ1,2%），7天未吸入异氟烷组（Ⅰ7,0），7天1．5％异氟烷组（Ⅰ7,1.5%），7天2％异氟烷组（Ⅰ7,2%）。吸入异氟烷后在第1天和第7天分别进行Morris水迷宫测试，每天8次，连续5天。以定位航行实验中到达平台的潜伏期作为学习成绩，以空间探索实验中在1min内通过平台位置的次数作为记忆成绩。结果吸入1．5％和2％异氟烷1天后痴呆模型大鼠的定位航行实验和空间探索实验的成绩均明显低于未吸入异氟烷组大鼠，其中吸入2％异氟烷大鼠的成绩最差（P〈0．05）。吸入不同浓度的异氟烷7天后，各组大鼠定位航行实验和空间探索实验的成绩没有明显差异（P〉0．05）。结论异氟烷可以使VaD老年大鼠学习记忆能力进一步下降，但这种作用是短期的。

Effects of isoflurane on the learning and memory in aged rats with vascular dementia

Objective To investigate the effects of isoflurane at different concentrations on the learning and memory in aged rats with vascular dementia. Methods The model of aged rats with vascular dementia was established with the method of 4 -vessel occlusion （4 -VO） in 60 aged SD rats （30 males and 30 females）. The animals were divided into 6 groups according to the days （days 1 and 7 ） after isoflurane inhalation and the isoflurane concentrations （0, 1.5% and 2.0% ） ： d1 0 isoflurane group （Ⅰ1,0）, dl 1.5% isoflurane group （Ⅰ1,1.5%）, d1 2.0% isoflurane group （Ⅰ1,2%）, d7 0 isoflurane group （Ⅰ7,0） , d7 1.5% isoflurane group （Ⅰ7,1.5%） and d7 2.0% isoflurane group （Ⅰ7,2%）. On day 1 and day 7 after isoflurane inhalation, Morris water maze testing was performed 8 times every day for 5 consecutive days. The latency of reaching platform in place navigation performance was the score of learning and the frequency of passing the position of platform within 1 min in probe trial performance was the score of memory. Results On the 1 st day after isoflurane inhalation, the scores in the place navigation and probe trial performance of 1.5% and 2.0% isoflurane groups were markedly lower than those of 0 isoflurane group, of which the 2.0% isoflurane group had the lowest scores （P 〈 0.05）. On the 7th day after isoflurane inhalations, no significant differences were observed in the latency and frequency among three groups （P 〉 0.05 ）. Conclusion Isoflurane can further impair the learning and memory in aged rats with vascular dementia, only temporarily though.