红藻氨酸诱导癫发作大鼠海马星形胶质细胞C-FOS基因表达的研究

C-FOS gene expression of hippocampal astrocytes in epilepsy rats induced with kainic acid

目的研究癫发作大鼠海马星形胶细胞C-FOS基因表达的变化,探讨其对癫发作的维持与复发的影响。方法将83只成年雄性SD大鼠随机分为实验组58只,对照组25只。实验组在海马CA3区注射红藻氨酸(Kainicacid,KA)建立癫模型,对照组在相同部位注射等量生理盐水。利用免疫组织化学双重染色技术,分别在癫发作后1h、3h、6h、12h和24h观察大鼠海马星形胶质细胞C-FOS基因的表达。结果与对照组大鼠比较,癫模型鼠海马CA1区CFAP/C-FOS双标记阳性细胞百分率于癫发作后1h(12.70±0.03)、3h(17.10±0.05)、6h(24.92±0.04)明显升高(P<0.01),在6h达到高峰,在12h下降,但是仍较对照组高(10.71±0.06;1.59±0.02,P<0.01),在24h下降至对照组水平(2.00±0.02;2.08±0.03,P>0.05)。结论KA诱导大鼠癫发作,导致海马星形胶质细胞C-FOS基因相对持续的高表达,从而激活星形胶质细胞,产生高致性的病理环境,可能是癫发作的维持以及复发的病理生理机制之一。

Objective To investigate the time course of expression of C-FOS gene in hippocampal astrocytes in rats after seizure activity, and its impacts on sustain and relapse of epilepsy. Methods A model of epilepsy rats induced with kainic acid was established. The expressions of C-FOS gene in hippocampal astrocytes were observed using double immunocytochemical staining at 1 ^st h, 3^rd h, 6^th h, 12^th h and 24^th h from onset of seizure, respectively. Results Compared with the controls, the percentage of GFAP/C-FOS positive cells in CA1 area of hippocampus of epilepsy rats rised 1 h （ 12. 70 ＋0. 03）, 3 h（ 17.10 ＋0. 05）, 6 h（24.92 ＋0. 04） after seizure （P 〈0. 01 ）, and began to fall from 12 h to 24 h after seizure. The percentage returned to the level of control group 24 h after seizure （ 2. 00 ＋ 0.02 ; 2.08 ＋ 0.03, P 〉 0.05 ）. Conclusions The increased expressions of C-FOS gene in astrocytes in epilepsy rats may play a role in sustain and relapse of seizure through activating the hippocampal astrocytes, and shaping a circumstance in which seizure either tends to sustain for a longer time or to relapse.