海洛因依赖大鼠海马必需氨基酸含量与学习记忆关系的初步探讨

PRELIMINARY STUDY ON RELATIONSHIP BETWEEN CONTENT CHANGES OF ESSENTIAL AMINO ACIDS IN HIPPOCAMPUS AND LEARNING AND MEMORY OF HEROIN DEPENDENT RATS

[目的]探讨海洛因依赖大鼠海马必需氨基酸含量变化与学习记忆功能的关系。[方法]按剂量逐日递增原则,首日每次剂量为3mg/kg,1日2次,连续9d皮下注射海洛因建立海洛因依赖SD大鼠模型;对照组以同样方式注射等量生理盐水。用Morris水迷宫检测两组大鼠学习记忆功能,另取大鼠海马用氨基酸自动分析仪测定必需氨基酸含量。[结果]海洛因依赖大鼠第Ⅲ象限活动时间和第Ⅲ象限游泳距离占总游泳距离百分比均较对照组明显降低(P﹤0.05),并且依赖大鼠海马缬氨酸的含量显著高于对照组(P﹤0.05);苯丙氨酸、赖氨酸、异亮氨酸、蛋氨酸和苏氨酸5种必需氨基酸中的几种虽为微量或含量在组间比较差异无统计学意义(P﹥0.05),但均表现出增加的趋势。[结论]大鼠海马几种必需氨基酸含量的改变可能与海洛因依赖造成的学习记忆损害有关。

[Objective] To study the relationship between content changes of essential amino acids in hippocampus and learning and memory of heroin dependent rats. [ Methods] Heroin was injected subcutaneously with 3 mg/kg on the first day, twice a day for 9 days according to the principle of daily increasing dose to establish the heroln-dependent Spragne-Dawtey rat models. The saline solution of equal dose was administrated in control group. The spatial learning and memory abihty was tested with Morris water maze and the content of essential amino acids in hippocampus of rats was measured with Amino-acid automatic analyser. [Results] The time spent in the third platform quadrant of heroin-dependent rats and the ratio of the third to the total platform quadrant distance were significantly less than those in control group （P 〈 0.05）. The valine content in hippocampus of heroin-dependent rats was significantly higher than that in control group （P 〈 0.05）. There was a increasing trend in the contents of phenylalanine,lysine, isoleucine, methionine and threonine although some of them were scanty or were not different significantly in the content between two groups （P 〉 0.05 ）. [ Conclusions] The content changes of several essential amino acids in hippocampus may be related to the impairment on learning and memory of the heroin-dependent rats.