在体微透析检测豚鼠胆红素脑病模型脑组织兴奋性氨基酸神经递质

Microdialysis of Hippocampus for Measurement of the Neurotransmitter in Bilirubin Induced Encephalopathy Guinea Pigs in Vivo

目的 探讨胆红素脑病动物模型制作及其脑组织中兴奋性氨基酸 (EAA)神经递质变化。方法 豚鼠腹腔内给予胆红素 2 0 0 μg/g后 8h ,电镜观察脑组织形态结构 ,在体脑内微透析提取神经突触间细胞外液 ,HPLC检测分析天冬氨酸 (Asp) ,谷氨酸 (Glu)和甘氨酸 (Gly)。结果 胆红素毒性脑组织神经元及其线粒体肿胀 ,细胞外Gly含量为2 1 .35± 4.87μM ,明显高于对照组1 4 .0 2± 1 .5 6 μM (P <0 .0 1 ) ;胆红素毒性脑组织细胞外Asp ,Glu与对照组比较差异不显著 (P >0 .0 5 )。结论 胆红素毒性脑组织细胞外甘氨酸 (Gly)含量增加 ,可提高NMDA受体对EAA神经递质Asp及Glu敏感性 ,致NMDA受体过度活化。

Objective To study the excitatory amino acid (EAA) neurotransmitter concentration in bilirubin induced encephalopathy. Methods Guinea pigs with bilirubin-induced encephalopathy were fixed in the stereotaxic frame. The microdialysis probe was inserted in the hippocampus zone, Kreb's ringer was irrigated and extracellular liquid was collected for analyses with high performance liquid chromatography (HPLC). Results The concentration of EAA neurotransmitter Gly in the extracellular liquid of the bilirubin precipitated brain was 21.35±4.87 μM,significantly higher than that in the control group (14.02±1.56μM). EAA neurotransmitter Glu and Asp did not show any significant change in the animal model compared with the control. Conclusions The increase of EAA neurotransmitter Gly concentration in the extracellular liquid of the bilirubin precipitated brain tissues might increase the sensitivity of the ligand Asp and Glu to the NMDA Receptor.