代谢型谷氨酸受体1α在大鼠脑缺血再灌注损伤中的基因表达变化

Changes in expression of metabotropic glutamate receptor 1α induced by focal cerebral ischemia and reperfusion in rats

目的 观察大鼠大脑中动脉闭塞 (MCAO)后再灌注不同时点代谢型谷氨酸受体 1α(mGluR1α)的蛋白与基因表达的变化 ,以探讨其在脑缺血再灌注损伤中的意义。方法 4 8只SD大鼠随机分为假手术组及缺血 2h再灌注 1、3、6、12、2 4、4 8及 72h组 ,用免疫组织化学、逆转录 聚合酶链反应 (RT PCR)技术和HE染色检测各组mGluR1α的蛋白表达、mRNA转录水平及坏死神经元的计数。结果 各缺血再灌注组mGluR1α表达均高于假手术组 ,再灌注 1hmGluR1α的mRNA转录即有升高 ,6h达到高峰 ,mGluR1α蛋白表达从 3h开始增加 ,12h达高峰 ,与神经元损伤程度一致。结论 脑缺血再灌注可引起mGluR1α表达上调 ,且与神经元损伤程度平行 ,提示mGluR1α参与介导了局灶性脑缺血再灌注损伤。

Objective To investigate the expression of metabotropic glutamate receptor 1α(mGluR1α) in focal cerebral ischemia in rats, and to explore its role in ischemic neuronal injury.Methods Forty-eight SD rats were divided into 8 groups,of which,one group received sham surgery (SS),and the other 7 groups received 2 h middle cerebral artery occlusion (MCAO) followed by reperfusion for 1 h,3 h,6 h,12 h,24 h,48 h and 72 h respectively.The immunoreactivity and mRNA level of mGluR1α and number of damaged neurons were evaluated in each group.Results Compared with the SS group,the transcription of mGluR1α mRNA was elevated from 1 h and peaked within 6 h after reperfusion,and the increase in expression of mGluR1α started at 3 h and reached its peak within 12 h.Meanwhile there was a same time-course in ischemic neuronal injury.Conclusions It is suggested that up-regulation of mGluR1α might be a key event in the neuronal injury induced by cerebral ischemia-reperfusion.