自发性癫痫大鼠脑内海马Ⅲ型电压门控性钠通道N亚型表达上调

The regulated-up of expression of type Ⅲ voltage-gated sodium channel ⅢN in spontaneously epileptic rat brain hippocampus

[目的]对照研究自发性癫痫大鼠(SER)和正常 Wistar 大鼠(WTC)脑内Ⅰ、Ⅱ、Ⅲ型钠通道α亚基mRNAs与蛋白表达情况。[方法]提取枕叶皮质、齿状回及海马 CA1和 CA3区组织总 RNA,应用逆转录-聚合酶链反应(RT-PCR)及建立限制性内切酶图谱检测Ⅰ、ⅡA、ⅡN、ⅢA和ⅢN的表达.应用免疫荧光定位与表达α_3亚基川 N 蛋白。[结果]SER枕叶皮质、齿状回及海马CAl和CA3区总钠通道的表达略高于 WTC,但均无显著差异(P>0.05),SERⅢ型钠通道在海马的表达高于 WTC(P<0.01),酶切图谱显示ⅢN型钠通道表达水平有明显上调。[结论]SER 脑内海马Ⅲ型电压门控性钠通道 N 亚型表达上调。

[Objective] To compare the expression of coding voltage dependent Ⅰ,Ⅱ and Ⅲ sodium channel α-isoform in spontaneously epileptic rats(SER)and control rats.[Methods] Total RNA is extracted from occipital cortex,dentate gyrus,CA_1 and CA_3 hippocampus,all types sodium channel are observed using PCR A protocol after reverse transcription,and the expression of type Ⅰ,Ⅱ A,Ⅱ N,Ⅲ and ⅢA,ⅢN sodium channels is respectively determined after restricted digestion of PCR B,C and D products.Type ⅢN sodium channel protein expression is detected by immunofluoresence.[Results] In spontaneously epileptic rats,all types of sodium channel expresse in a higher level than those of control groups in occipital cortex,dentate gyms,CA_1 and CA_3 hippocampus without significant difference(P>0.05).Relative proportion of sodium channel Ⅰ,Ⅱ,Ⅱ and Ⅲ mRNAs in four adult brain areas from control rats and SER have no significant difference(P>0.05).But type Ⅲ sodium channel expresses higher than that in control groups in hippocampus,restriction mapping analysis shows that ⅢN increases significantly(P<0.01).[Condusion] The expression of type Ⅲ sodium channel ⅢN is up regulated in hippocampus of spontaneously epileptic rat brain.