【摘要】 目的研究茶氨酸对大鼠局灶性脑缺血再灌注损伤的保护作用。方法将SD雄性大鼠按体重随机分为5组,分别为模型对照组、假手术组、茶氨酸低剂量组(10mg/kg)、中剂量组(30mg/kg)、高剂量组(90mg/kg)。大鼠灌胃给予茶氨酸15天后采用大脑中动脉栓塞法制备MCAO模型,在再灌注后3h、24h进行神经学评分,再灌注24h后处死动物,测定脑指数及脑组织中天门冬氨酸(Asp)、谷氨酸(Glu)、甘氨酸(Gly),γ-氨基丁酸(GABA)和茶氨酸含量,并采用RT-PCR法检测海马组织中脑源性神经营养因子BDNFmRNA以及Bcl-2 mRNA的表达水平。结果与模型组相比,茶氨酸各剂量组大鼠的神经症状明显改善、脑水肿程度较低;神经递质Asp含量降低,Gly、GABA含量升高,且存在一定的剂量效应关系;茶氨酸剂量组大鼠海马组织中BDNF mRNA和Bcl-2 mRNA表达均显著高于模型对照组(P<0.05)。结论茶氨酸对大鼠脑缺血再灌注引起的神经损伤具有一定的保护作用,其机制与调节氨基酸类神经递质以及上调BDNFmRNA和Bcl-2 mRNA表达有关。更多还原

【Abstract】 Objective To study the protective effect of theanine on cerebral ischemia-reperfusion injury induced by focal cerebral ischemia in rats.Method Sprague-Dawley rats were randomly assigned into five groups: model group,shame(SH) control group and 3 theanine groups(Th-L,Th-M and Th-H).The rats in model and SH groups were given distilled water,and the rats in Th groups were given theanine solution(10,30 and 90 mg/kg respectively) intragastrically for 15 days.Then the cerebral ischemia-reperfusion injury was established by middle cerebral artery occlusion(MCAO) in the model and Th groups,and SH group was used as a fake surgery control.The score of neurological behavior was evaluated at the 3rd and 24th hours after reperfusion.Rats were sacrificed at 24h after reperfusion,and the brain index was measured.The concentrations of aspartic acid(Asp),glutamic acid(Glu),glycine(Gly),γ-aminobutyricacid(GABA) and theanine(The) in rat brain following ischemia-reperfusion were determined.The expressions of BDNF mRNA and Bcl-2 mRNA in hippocampi were examined by reverse transcription polymerase chain reaction(RT-PCR) technique.Results Compared with model control group,the neurological deficits of theanine treated groups were milder;and the symptoms were more gently.The concentration of neurotransmitter Asp was lower while the Gly and GABA were higher,and a trend of dose-effect relation was existed.The expressions of BDNF mRNA and Bcl-2 mRNA in hippocampi were up-regulated in the theanine treated groups compared with model group(P<0.05).Conclusion Theanine has a protective effect on cerebral ischemia-reperfusion injury in rats,which may be associated with its interaction with amino acid neurotransmitters and up-regulating the expression of BDNF mRNA and Bcl-2 mRNA.更多还原