氯巴占耐受听源性惊厥大鼠脑GABA_A受体亚单位表达的变化

目的　探讨氯巴占耐受听源性惊厥大鼠中枢GABAA受体亚单位表达的变化和这种改变与氯巴占耐受性机制关系。方法　腹腔注射氯巴占 2wk ,产生听源性惊厥大鼠氯巴占耐受模型。用竞争性定量RT PCR测定大鼠脑皮质运动区和海马区的GABAA 受体α1、α3、α5、γ2L和γ2S亚单位mRNA的含量。结果　氯巴占耐受组大鼠皮质运动区α1亚单位下降 2 7% ,α5上升 73% ,γ2L下降 4 3% ,γ2S下降 37% ;海马区的α1下降 2 8% ,γ2L下降 32 % ,γ2S下降 31% ,与对照组相比差异均有显著性。结论　听源性惊厥大鼠的氯巴占耐受机制与中枢GABAA 受体α1、α5、γ2L和γ2S亚单位表达的适应性改变有关

Modification of brain GABA_A receptor subunit α1,α3,α5,γ2L and γ2S expression in audiogenic seizure rat following tolerance to clobazam

AIM To investigate the modification of GABA A receptor subunits in audiogenic seizure rat cortex and hippocampus when rendered tolerant to clobazam. METHODS Rats were administrated with clobazam for two weeks, resulting in tolerance to clobazam. GABA A receptor subunit α1, α3, α5, γ2L and γ2S were assayed using quantitative competitive RT PCR in rat FrPaM and hippocampus. RESULTS In FrPaM,the content of mRNA encoding for α1,γ2L and γ2S were all significantly decreased (27%,43% and 37% respectively),whereas that of α5 was significantly increased (73%) compared with the control. In hippocampus, α1, γ2L, and γ2S mRNA content was significantly decreased (28%, 32% and 31% respectively). CONCLUSION The accomodated change in GABA A receptor subunit α1, α5,γ2L and γ2S in FrPaM and hippocampus may be associated with the mechanism for tolerance to clobazam in audiogenic seizure rat.