【摘要】 目的探讨地塞米松(Dex)对颞叶癫痫大鼠海马NMDA受体亚单位NR2A、NR2B表达的影响。方法将雄性Wistar大鼠随机分为正常组、假手术组(Sham组)、生理盐水预处理后颞叶癫痫点燃组(TLE组)和小剂量Dex短期预处理后颞叶癫痫点燃组(Dex组)。应用海人酸杏仁核点燃建立经典颞叶癫痫模型,采用原位杂交方法检测点燃或假手术后海马神经元NR2AmRNA、NR2BmRNA的时空表达。结果正常组和Sham组海马总体和各区NR2AmRNA阳性细胞表达无差异(P>0.05);与Sham组比较,TLE组24h、7d、14d、21d NR2AmRNA表达增高(P<0.05),点燃后21d以海马CA1区和齿状回(DG)表达增高为主(P<0.05);Dex组在点燃后6h明显高于TLE组,在7d、14d、21d低于TLE组(P<0.05),点燃后21d海马CA1区和DG均低于TLE组(P<0.05)。正常组和Sham组CA3区NR2BmRNA表达高于CA1区和DG(P<0.05),TLE组和Dex组DG表达高于CA1和CA3区(P<0.05),Dex组21d海马各区表达均高于TLE组(P<0.05)。结论颞叶癫痫大鼠海马NR2A和NR2B表达出现时空表达变化。小剂量Dex可减轻颞叶癫痫引起的海马NR2A和NR2B表达失衡,可能是其发挥抗颞叶癫痫和脑保护作用的机制之一。更多还原

【Abstract】 Objective To explore the effect of dexmethasone on the expressions of the subunits NR 2 A and NR 2 B of NMDA receptors in hippocampus in temporal lobe epileptic rats after kindling. Methods Male Wistar rats were randomly divided into normal group,sham group,natrium saline pretreatment group before kindling( TLE group) and Dex pretreatment group prior to be kindled( Dex group). Typical temporal lobe epileptic model was kindled by Kainic acid( KA) microinjected into right Nucleus amygdalae. In situ hybridization was used to spatio-temporally observe the expression of NR 2 AmRNA and NR 2 BmRNA in hippocampus after kindling or sham operating in rats. Results There was no difference of positive cell count( PCC) of NR 2 AmRNA expression in hippocampus between Sham group and normal group both in total and in each hippocampal subarea( P > 0. 05). Compared to Sham group,NR 2 AmRNA expressed higher at 24h,7d,14d,21d after kindling( P < 0. 05),and enhanced in CA 1 and DG regions both in total and on 21d after kindling( P < 0. 05). While,compared to TLE group,NR 2 AmRNA increased at 6h in Dex group( P < 0. 05),and decreased on 7d,14d,21d after kindling( P < 0. 05),especially declined in CA 1 and DG regions both in total and on 21d in Dex group than that of TLE group after kindling( P < 0. 05). In general,NR 2 BmRNA expressed higher in CA 3 region than that in CA 1 and DG regions in Sham and normal groups( P < 0. 05). However,in TLE and Dex groups,its expression was increased in DG than that in CA 1 and CA 3 regions( P < 0. 05),and it was enhanced in each subareas in hippocampus in Dex group than that of TLE group( P < 0. 05). Conclusion There are temporal and spatial changes of NR 2 A and NR 2 B expressions in hippocampus in TLE rats. Low-dose dex may play its antiepileptic and protective role via alleviating temporospatial unbalance of the expression of NR 2 A and NR 2 B in hippocampus in temporal lobe epilepsy.更多还原