谷氨酸对大鼠不同脑区神经毒性的比较研究

COMPARATIVE STUDY NEUROTOXICITY OF MONOSODIUM GLUTAMATE ON DIFFERENT PARTS OF RAT BRAIN

目的 :探讨谷氨酸神经毒性在不同脑区的差异。方法 :新生 SD大鼠 2 9只 ,生后第 3至第 9天 ,分为 1g/ kg、2 g/ kg、3g/ kg 3组 ,腹腔内注射谷氨酸单钠 ( monosodium glutamate,MSG) ,并设空白对照组和注射生理盐水组。 3月龄时取脑作石蜡切片 ,Spoerri氏法染色。光镜下计数丘脑、下丘脑、杏仁核、海马、齿状回、梨状皮质等 16个脑区的神经元数 ,并进行统计学分析。结果 :多数脑区注射 MSG后神经元减少 ,并与注射量呈正相关 ,但齿状回、尾 -壳复合体无明显变化 ,背侧内梨状核、杏仁内侧核、海马 CA3区和海马 CA4区的神经元 ,在低剂量组无明显减少 ,而在中、高剂量组明显减少。结论 :MSG对不同脑区的损伤程度不同 ,有些脑区具有某种保护机制 。

Objective: To research the differences of neurotoxicity of glutamic acid(Glu) on different parts of the brain in rat. Methods: Twenty nine newborn SD rats were divided into 3 experimental groups and a control group. From third to ninth days after birth, the experimental rats were injected intraperitoneally with MSG 1 g/kg, 2 g/kg and 3 g/kg BW every day and controls were given normal saline or untreated. After surviving for 3 months, all the rats were perfused, and their brain were made into sections and stained by Spoerris technique. The neurons of 16 parts of the brain were enumerated with light microscopy. Results: The neurons decreased markedly in most parts of the brain in the experimental rats. But in the dentate gyrus and caudate putamen complex, the quantity of neurons was unchanged. Moreover, in the nucleus dorsal endopiriform, nucleus amygdalae medialis, fields CA3 and CA4 of hippocampus, neurons were unchanged when the dose of MSG was lower, and when dose of MSG increased, neurons decreased markedly. COnclusion: Neurons in some part of brain are protected from the MSG.