摘要
目的 观察G蛋白偶联内向整流钾通道 (GIRK)亚基GIRK2mRNA和蛋白在红藻氨酸致大鼠海马表达的时空变化 ,探讨其在癫发生发展中的作用。方法 采用红藻氨酸致颞叶癫大鼠模型 ,运用原位杂交和免疫细胞化学检测不同时间点大鼠海马齿状回 (DG)、CA1、CA3 区GIRK2mRNA和蛋白表达。结果 GIRK2mRNA和蛋白在大鼠海马内分布广泛 ,表达丰富 ;大鼠腹腔注射红藻氨酸后 ,GIRK2mRNA在DG区表达逐渐增多 ,12h(实验组 0 4 2 36± 0 0 380 ,对照组 0 3396±0 0 343)、2 4h(实验组 0 4 2 5 3± 0 0 4 37,对照组 0 3173± 0 0 315 )达到高峰 ,与对照组比较差异有显著性意义 (P <0 0 1) ;此后逐渐下降 ,但仍高于对照 ;30d又达到高峰 (P <0 0 1) ;致大鼠海马内GIRK2蛋白仅DG区在 30d时与对照组比较增高有显著意义 (P <0 0 1)。结论 GIRK2mRNA和蛋白在癫大鼠海马内表达增高 ,特别是在DG区 ,提示GIRK2增高是机体对神经元过度兴奋的代偿或适应性反应 ;其合成增加将降低神经元的兴奋性 ,阻止海马内过度兴奋在DG→CA3 →CA1方向的扩散。
Objective To report the mRNA and protein expression of GIRK subunit 2 altered in kainic acid (KA)-induced epileptic rat hippocampus.Methods Rats were injected with kainate 14 mg/kg intraperitoneally to establish an acute and chronic temporal lobe epilepsy model. At 3 h,6 h,12 h,24 h,48 h,7 d,30 d after KA induced seizures,by using in situ hybridization and immunocytochemistry,the GIRK2 mRNA and protein were analyzed at different time quantitatively in the dentate gyrus,CA 1,CA 3 regions of hippocampus.Results GIRK2 mRNA and proteins were expressed abundantly in all regions of hippocampus. KA induced seizures caused a significant increase in GIRK2 mRNA abundance at 12 h (0.4236±0.0380 vs 0.3396±0.0343),24 h (0.4253±0.0437 vs 0.3173±0.0315) and 30 days (0.4425±0.0924 vs 0.3377±0.0361) time point,accompanying an only increase in GIRK2 immunoreactivity in the DG area at 30 d point.Conclusion Changes in mRNA and protein expression of GIRK2 in the hippocampus of epileptic rat brain should be up-regulated,which might be an adaptive response to over-excitability of neuron networks and prevent the over-excitability to spread in hippocampus (DG→CA 3→CA 1).
出处
《中华神经科杂志》
CAS
CSCD
北大核心
2004年第3期224-227,共4页
Chinese Journal of Neurology
