摘要： 目的  研究颞叶癫痫模型海马区神经元Akt1 表达变化，探讨其在癫痫发生发展中的作用。方法  采用氯化锂-匹罗卡品方法制备颞叶癫痫大鼠模型，Western blotting 检测海马区总蛋白、Quantity one 软件行灰度值分析；免疫组织化学染色观察海马各区Akt1 蛋白表达变化，计数不同处理组阳性神经元数目。结果  Western blotting 检测结果显示，与正常对照组相比，癫痫模型组大鼠于癫痫持续状态发作即刻海马区Akt1 蛋白表达升高（t = 2.445，P = 0.034），并于第30 天时达峰值水平（t = 1.214，P = 0.002），发作后24 h 表达水平迅速降低，并低于正常值范围（t = 4.294，P = 0.000），其余各测量时间点表达无明显改变；与氯化锂组相比，癫痫模型组大鼠于癫痫持续状态后1 h 海马区Akt1 蛋白表达开始降低，24 h 降至最低水平（t = 4.134，P = 0.000），至发作48 h 后开始逐渐升高（t = 2.481，P = 0.002），并于发作第7 天时升至氯化锂组水平。免疫组织化学染色显示，癫痫持续状态发作后海马CA3 区Akt1 蛋白表达阳性神经元数目立即增加，12 h 达高峰（t = 16.586，P = 0.000），48 h 减少并降至正常值水平（t = 0.357，P =0.089），发作后第10 天再次增加（t = 3.123，P = 0.000），于第30 天时阳性神经元数目再次达峰值水平（t =18.339，P = 0.000），第50 天开始恢复至正常值水平（t = 3.219，P = 0.000）；氯化锂组仅海马CA3 区Akt1 蛋白表达于实验初始（0 h）升高并高于正常对照组（P < 0.05），海马CA1 和CA2 区Akt1 蛋白表达变化组间差异均无统计学意义（P > 0.05）。结论  海马及海马CA3 区Akt1 蛋白表达均呈现癫痫持续状态后升高、降低、再升高的动态过程，提示可能存在神经元保护作用，对抗细胞凋亡、促进细胞存活。

关键词: 蛋白激酶类； 海马； 癫痫； 免疫印迹法； 免疫组织化学； 疾病模型, 动物

Abstract: Objective To study the expression of Akt1 in hippocampal neurons in temporal lobe epilepsy, and explore its role in the development of epilepsy. Methods Two hundred and ten healthy adult male Sprague-Dawley (SD) rats were randomly divided into normal group (n = 10), lithium chloride (LiCl) group (n = 10) and epilepsy group (n = 190). LiCl-pilocarpine (PILO) was used for animal model of epilepsy. Total protein was extracted from hippocampus and rat brain slices were obtained at different time points (0 h, 1 h, 6 h, 12 h, 24 h, 48 h, 7 d, 10 d, 30 d, 50 d) after status epilepticus (SE) in normal group and LiCl group. Western blotting technique was used for detection of total protein in the hippocampus, and gray value was analyzed by Quantity one software. Immunohistochemical staining was used to detect the expression of Akt1 protein in the hippocampus and microscopic counting method (× 200) was used to quantify positive nerve cells in hippocampal region. Results Compared with the control group, the expression of Akt1 protein in the hippocampus in epilepsy group was significantly increased at the beginning of SE and achieved to the peak at 30 d after SE (0 h: 4.09±0.04, t = 2.445, P = 0.034; 30 d: 0.52± 0.03, t = 1.214, P = 0.002). The expression level was quickly reduced and was lower than normal value at 24 h after SE (0.27 ± 0.06, t = 4.294, P = 0.000), and no significant differences were seen at other time points. In comparison with LiCl group, the Akt1 protein expression in hippocampus in epilepsy group began to decrease at 1 h after SE, and reached to the lowest level at 24 h after SE (0.27 ± 0.06, t = 4.134, P = 0.000). At 48 h after SE the Akt1 expression began to increase and achieved to the level of LiCl group at 7 d after SE. In immunohistochemical staining: Akt1 protein positive cells in hippocampal CA3 area immediately increased after SE and achieved to the peak (46.70 ± 2.90) at 12 h after SE, but decreased to normal level (16.20 ± 2.50) at 48 h after SE. The positive neurons increased again (25.00 ± 2.30) at 10 d and reached to peak level (44.10 ± 1.80) again at 30 d after SE, but began to reduce to normal level (22.30 ± 2.60) at 50 d after SE. In LiCl group, Akt1 protein expression in CA3 area was higher than that in normal group at 0 h (P < 0.05). Akt1 protein positive cells in CA1 and CA2 areas showed no significant difference among different groups (P > 0.05, for all). Conclusion The dynamic process of Akt1 protein expression in hippocampus and the CA3 area of hippocampus after SE showed a higher, lower, and then higher presentation, suggests a possible cellular protective effect against apoptosis and promotion for cell survival.

Key words: Protein kinases, Hippocampus, Epilepsy, Immunoblotting, Immunohistochemistry, Disease models, animal