代谢型谷氨酸受体在脑损伤后的表达及意义

Alteration and significance of metabotropic glutamate receptors groupⅠ,Ⅲ mRNA of cerebral cortex in diffuse brain injury

目的 :探讨弥漫性脑损伤 (DBI)后大脑皮质代谢性谷氨酸受体 (m Glu Rs)的变化及其意义。方法 :SD大鼠随机分为对照组和 DBI组 ,采用 Marmarou加速性 DBI模型 ,在伤后不同时间取样行原位杂交和病理学研究。结果 :与对照组相比 ,DBI组大脑皮质 、 组 m Glu Rs (除 m Glu R6 外 )阳性神经元表达在伤后 12小时开始增加 ,2 4小时增加显著 (P<0 .0 1)。病理研究提示 ,DBI后 2 4小时大脑皮质神经元损伤严重 (P<0 .0 1) ,与m Glu Rs表达变化的时间吻合。结论 : 、 组 m Glu Rs作用不同 ,分别具有神经元损害和保护作用 ;脑损伤后 , 组 m Glu Rs表达增加 ,参与 DBI引起的神经元损伤 , 组 m Glu Rs表达增加 ,具有神经元保护作用 ,这为阐明DBI的损伤机制及运用 m Glu Rs激动剂和 (或 )拮抗剂治疗提供了理论依据。

Objective:To investigate the charges in metabotropic glutamate receptors (mGluRs) groupⅠ,Ⅲ mRNA of cerebral cortex in a rodent model of diffuse brain injury(DBI).Methods:SD rats were randomized into sham and DBI groups.Based on Marmarou′s rodent model of diffuse brain injury,the expressions of mGluRs were detected by in situ hybridization methods and the pathology of cerebral cortex was studied at different time after injury.The number of positive neurons and damaged neurons in each groups were counted under microscope,the experimental data were treated with statistical analysis.Results:Compared with that of sham group,counts of positive neurons in groupsⅠ,Ⅲ mGluRs increased at 12 hours and peaked at 24 hours,except mGluR6 mRNA which had no significant change.The count of damaged neurons in cerebral cortex was accordingly increased at 24 hours.Conclusions:mGluRs play different roles in DBI in which mGluRs groupⅠtakes part in the neuronal injury whilst mGluRs groupsⅡneuroprotection.This hypothesis might provide a theoretical basis for the treatment of DBI with agonist or antagonist of mGluRs.