脑缺血预处理对大鼠脑组织中氨基酸及肿瘤坏死因子-α含量的影响

Effect of cerebral ischemic preconditioning on content of amino acid and tumor necrosis factor-α in rats

目的研究脑缺血预处理(CIP)后大鼠脑组织中谷氨酸(Glu)、天冬氨酸(Asp)Asp、γ-氨基丁酸(GABA)甘氨酸(Gly)、肿瘤坏死因子-α(TNF-α)含量的变化及其作用。方法 90只雄性SD大鼠随机分为正常组、假手术组、实验组,各组又被分别分为1,3,6,12,24 h 5个亚组。用高效液相色谱法测定不同时间点脑组织中Glu、Asp、GABA及Gly的含量,用分光光度法测定TNF-α的含量。结果与假手术组比较,实验组的脑组织中Glu、Asp、GABA、Gly含量在1 h均明显增高(P<0.05,P<0.01),3 h后逐渐下降,24 h恢复正常水平。于预处理后1 h,TNF-α即开始升高(P<0.05),6 h达高峰,24 h仍高于正常水平(P<0.05)。结论 CIP后引起适度升高的Glu、Asp、GABA、Gly、TNF-α,可能是早期脑缺血耐受机制的启动物质。

Objective To explore the content change of glutamic acid（ Glu）,aspartic acid（ Asp）,glycine acid（ Gly）,γ-aminobutyric acid（ GABA）,tumor necrosis factor-α（ TNF-α） following a cerebral ischemic preconditioning（ CIP） and its function. Methods A total of 90 male Sprague-Dawley rats were randomly divided into 3 groups： normal group（ n = 30）,sham group（ n = 30） and experiment group（ n = 30）.The three groups were divided into hour-1, hour-3, hour-6,hour-12,hour-24 subgroups（ 6 in each subgroup）. The content of brain Glu,Asp,GABA,Gly were detected by HPLC. And TNF-α was detected spectrophotography in rats with the ischemic preconditioning and sham operation at different times（ 1,3,6,12,24 h）. Results Compared with those in the corresponding sham subgroups,the content of Glu,Asp,GABA,Gly began to significant increase at 1 h（ P〈0. 05 or P〈0. 01）,peaked at 1 h or 3 h and decreased to basal at 3 h or 6 h After CIP. the content of TNF-α began to increase at 1 h（ P〈0. 05）,peaked at 6 h and not decreased to basal at 24 h After CIP.Conclusion A moderate increase in Glu,Asp,GABA,Gly,TNF-αafter CIP might play a important role in the induction of the early brain ischemic tolerance mechanism.