氯胺酮对新生大鼠认知功能和海马突触素表达的影响

目的:观察氯胺酮对新生大鼠认知功能的影响及其机制以及对海马突触素的影响。方法:1周龄Wistar大鼠30只,随机分为3组,每组10只。对照组给予与氯胺酮组相同体积的等渗盐水;氯胺酮100 mg组和50 mg组麻醉诱导时分别腹腔注射氯胺酮100和50mg/kg,以后每小时追加首次剂量的1/2,维持麻醉6h。麻醉后21d进行旷场实验和Morris水迷宫实验,后取海马标本行突触素免疫组化染色,共聚焦显微镜观察并采集图像,用Image J图像处理软件分析荧光半定量A值。结果:氯胺酮可导致大鼠的认知功能的降低,海马突触素表达增加(P<0.05),氯胺酮100 mg组和50 mg组之间海马突触素表达无统计学意义(P>0.05)。结论:氯胺酮可降低新生大鼠的认知功能,并上调海马突触素表达。

Effects of ketamine on the cognitive function and hippocampus synaptophysin expression in neonatal rats

Objective: To observe the changes of the cognitive function and hippocampus synaptophysin in neonatal rats after ketamine administration.Methods: Thirty wistar rats at the age of 1w were randomly divided into 3 groups: a control group treated by saline with equal-volume to ketamine injection,a K 100 mg and a K 50 mg group given intraperitoneally 100 mg/kg and 50 mg/kg of ketamine respectively for anesthetic induction,and the anesthesia was maintained for 6 h by administering half a dose of inductive ketamine per hour.Open field and Morris water maze were tested at 21 days after anesthesia.Immunohistochemical techniques were used to observe the changes of hippocampus synaptophysin.Results:Compared with the control group,the retention time in the central check and the locomotion were not significantly different those of(P>0.05),the escape latency was longer(P<0.05) and the spatial probe test was shorter(P<0.05) in the experimental groups,with no significant difference between the K 100 and K 50 groups.Ketamine increased the expression of synaptophysin in the hippocampus(P<0.05) and no significant difference was noted between the two experimental groups.Conclusion: Ketamine may reduce the cognitive function and up-regulate the expression of hippocampus synaptophysin in neonatal rats.