应激对大鼠海马谷氨酸、天冬氨酸和γ-氨基丁酸含量的影响

目的　探讨应激对大鼠海马谷氨酸、天冬氨酸和γ 氨基丁酸 (GABA)含量的动态影响。方法　将 72只健康雄性大鼠随机分为 5个应激暴露不同时间组和对照组 ,每组 12只。利用高效液相色谱仪 紫外检测法 ,分别于应激第 1,3,7,14和 2 8天观察应激对大鼠海马谷氨酸、天冬氨酸及GABA含量的影响。结果　应激第 1天组大鼠海马谷氨酸和天冬氨酸含量与对照组相比 ,差异无显著性 ;但GABA含量 (2 74 7± 0 339) μmol/g]低于对照组 (3 719± 0 5 2 8) μmol/g;P <0 0 5 ]。应激第 3,7,14和 2 8天组谷氨酸含量 分别为 (7 818± 0 799) μmol/g ,(9 0 0 7± 0 5 2 0 ) μmol/g,(8 0 4 9± 0 733) μmol/g和 (8 12 9± 1 5 5 6 ) μmol/g]高于对照组 (6 4 11± 0 6 38) μmol/g];天冬氨酸含量 分别为 (2 717± 0 2 5 8)μmol/g,(2 6 96± 0 317) μmol/g,(2 82 8± 0 4 6 8) μmol/g和 (4 6 4 9± 0 6 37) μmol/g]也高于对照组 (2 0 0 3± 0 2 71) μmol/g];均P <0 0 1。应激第 14天组和 2 8天组GABA含量 分别为 (4 4 6 2± 0 883) μmol/g和(4 4 97± 0 85 7) μmol/g]高于对照组 (P <0 0 5～0 .0 0 1) ,应激第 3天组和 7天组的GABA含量与对照组间的差异无显著性。结论　应激第 3天开始

Effects of different stress sessions on glutamate, aspartate and gama-aminobutyric acid levels in rat hippocampal homogenate

ObjectiveTo explore the effects of different stress session on levels of excitatory amino acid, glutamate and aspartate, and inhibitory amino acid, gama-aminobutyric acid (GABA), in rat hippocampus. MethodsA total of 72 adult Sprague-Dawley male rats was exposed to daily 20-minute forced-swimming stress for at most 28 days. Every twelve rats as a group were put to death at the 0 (as control), 1, 3, 7, 14 and 28th day of stress, respectively. The hippocampal homogenate levels of glutamate, aspartate and gama-aminobutyric acid in each group were detected with high-perfomance liquid chromatography. ResultsCompared with control group, the levels of aspartate and glutamate in the first-day stress group were not changed ( P >0.05), but increased in the 3-, 7-, 14- and 28th-day group, respectively (all P <0.01). As to the GABA level, it was lower in the first-, day group than in control group ( P <0.05), but were significanty higher in the 14-, and 28th-day group compared with control group ( P <0.05). ConclusionThe levels of excitatory amino acid in rat hippocampus may be increased from the third-day of stress exposure, while the GABA levels decreased on the first-day and increased from the 14th-day.