酸枣仁汤对老年血亏阴虚失眠证候模型大鼠脑组织谷氨酸、γ-氨基丁酸及γ-氨基丁酸A受体表达的影响

Effects of Suanzaoren Tang on Glutamic Acid,γ-Aminobutyric Acid and γ-Aminobutyric Acid Subtype A Receptor Expression in Brain of Elderly Insomnia Model in Rats

目的:观察酸枣仁汤对老年血亏阴虚失眠证候模型大鼠脑组织谷氨酸(Glu)及γ-氨基丁酸(GABA)含量及GABAA受体α1和γ2亚单位表达的影响。方法:用D-半乳糖致亚急性衰老、环磷酰胺及氢化可的松致阴血亏虚,及自制改良多平台法剥夺睡眠48 h,制作复合型老年血亏阴虚失眠证候大鼠模型。采用高效液相色谱法检测模型大鼠大脑皮质及下丘脑氨基酸类神经递质Glu及GABA含量变化,采用免疫组化染色和mRNA半定量反转录-聚合酶链式反应(RT-PCR)法检测大脑皮质及海马部位γ-氨基丁酸A受体(GABAAR)α1和γ2亚单位的表达变化,并考察酸枣仁汤对这些指标的影响。结果:与环境对照组比较,证候模型组大鼠大脑皮质及下丘脑Glu及GABA含量显著升高(P<0.01,P<0.05),且Glu/GABA比值增高,大脑皮质及海马部位的GABAARα1和γ2亚单位免疫化学累积光密度明显较高(P<0.01),皮质部位GABAARα1和γ2 mRNA的表达均显著上调(P<0.01),经酸枣仁汤干预后各指标明显下降(P<0.01,P<0.05),并趋于正常范围。结论:皮质及海马部位GABAARα1和γ2亚单位表达的明显上调是老年失眠证候的可能病理机制之一,酸枣仁汤的治疗机制可能与其减少脑内氨基酸毒性作用,下调大脑皮质及海马部位GABAARα1和γ2亚单位的表达有关。

Objective：To observe the Effects of Suanzaoren Tang（SZRT） on glutamic acid（Glu）,γ-aminobutyric acid（GABA） and γ-aminobutyric acid subtype A rceptor（GABAAR） expression in the brain of the elderly insomnia model in rats.Method：Multiple factors model were established with subacute senescence induced by D-galactose,Yin and blood-deficiency induced by cyclophosphamide and hydrocortisonum,and sleep deprivation（SD） induced by a modified multiple platform method（MMPM）.The levels of amino acid neurotransmitters Glu and GABA were detected in cortex and hypothalamus for the rats by HPLC using immunohistochemical staining and semi-quantitative analysis of a retrovirus-polymerase chain reaction（RT-PCR）,subunit expression of GABAAR α1 and γ2 were detected in cortical and hippocampal parts of the model rats.After intervention of SZRT,thoseindicators were investigated too.Result：Compared with the environmental control group,content of Glu,GABA and the ratio of them in cortex and hypothalamus in the insomnia model rats showed a considerable elevatio,GABAARα1 and γ2 subunits expressed by immunochemical accumulated absorbance in cortex and hippocampus in the models were significantly higher（P 0.01）,and GABAARα1,γ2 mRNA expression in cortex showed higher significantly（P 0.01）.While these indicators tended to be in the normal range after the treatment of SZRT.Conclusion：Markedly up-regulated expression of GABAAR α1 and γ2 in cerebral cortex and hippocampus may be one of the pathological mechanisms for the insomnia model with sleep deprivation.SZRT can reduce the toxic effects of amino acids in brain,and downward adjust GABAAR α1 and γ2subunit expression in the brain.This may be one of the mechanisms for SZRT treatment of insomnia.