摘要目的:探讨缝隙连接蛋白Cx43抑制剂甘珀酸(CBX)对癫痫大鼠认知功能的影响及其可能的机制。方法:120只Wistar大鼠按随机数字表法分为假手术组、癫痫组、癫痫+溶剂组、癫痫+CBX组，每组30只。后3组大鼠海马内注射海人酸(KA)制备颞叶癫痫模型。癫痫+CBX组大鼠造模前30 min腹腔注射CBX(20 mg/kg)，癫痫+溶剂组大鼠造模前30 min腹腔注射等量生理盐水。造模后6、12、24 h采用Western blotting检测大鼠海马CA3区磷酸化(p)-Cx43和微管相关蛋白轻链3(LC3)的表达，造模后24 h采用免疫组化染色检测大鼠海马CA3区p-Cx43和LC3的定位及其阳性细胞的吸光度值，造模后30 d采用Morris水迷宫实验检测大鼠空间学习记忆能力的变化。结果:Western blotting检测结果显示，与假手术组比较，癫痫组、癫痫+溶剂组大鼠造模后6 h、12 h、24 h海马CA3区p-Cx43、LC3蛋白的表达均增加；与癫痫组、癫痫+溶剂组比较，癫痫+CBX组大鼠各时间点海马CA3区p-Cx43、LC3蛋白的表达均降低，差异均有统计学意义( P<0.05)。免疫组化染色检测结果显示，p-Cx43定位于海马星形胶质细胞的细胞膜和细胞质中，LC3定位于海马神经元胞质内。与假手术组比较，癫痫组、癫痫+溶剂组大鼠海马CA3区p-Cx43、LC3阳性细胞的吸光度值增加；与癫痫组、癫痫+溶剂组比较，癫痫+CBX组大鼠海马CA3区p-Cx43、LC3阳性细胞的吸光度值降低，差异均有统计学意义( P<0.05)。Morris水迷宫实验结果显示，与假手术组比较，癫痫组、癫痫+溶剂组大鼠的逃避潜伏期明显延长；与癫痫组、癫痫+溶剂组比较，癫痫+CBX组大鼠的逃避潜伏期明显缩短，差异有统计学意义( P<0.05)。 结论:CBX通过抑制癫痫大鼠海马CA3区星形胶质细胞p-Cx43蛋白的表达，减弱神经元自噬，从而减轻其认知功能损害。

abstractsObjective:To investigate the effect of gap junction protein Cx43 inhibitor carbenoxolone (CBX) on cognitive function and its possible mechanism in epileptic rats.Methods:One hundred and twenty Wistar rats were randomly divided into sham-operated group, epilepsy group, epilepsy+solvent group, and epilepsy+CBX group ( n=30). The models of temporal lobe epilepsy in the later three groups were prepared by injection of kainic acid in the hippocampus. Intraperitoneal injection of CBX (20 mg/kg) or equal amount of normal saline were given to the rats in the epilepsy+CBX group and epilepsy+solvent group 30 min before modeling. Western blotting was used to detect the protein expressions of phosphorylated (p)-Cx43 and microtubule associated protein light chain 3 (LC3) in the hippocampus 6, 12, and 24 h after modeling; the protein localization of p-Cx43 and LC3 in the hippocampus and optical density of their positive cells were detected by immunohistochemistry 24 h after modeling; the learning and memory abilities of rats were tested by Morris water maze experiment 30 d after modeling. Results:Western blotting results showed that as compared with those in the sham-operated group, p-CX43 and LC3 protein expressions in the hippocampal CA3 regions of epilepsy group and epilepsy+solvent group were significantly increased at 6, 12 and 24 h after modeling ( P<0.05); as compared with the epilepsy group and epilepsy+solvent group, the epilepsy+CBX group had statistically decreased p-CX43 and LC3 protein expressions in the hippocampal CA3 regions at each time point ( P<0.05). Immunohistochemical staining showed that p-CX43 was localized at the cell membrane and cytoplasm of hippocampal astrocytes; LC3 was located at the cytoplasm of hippocampal neurons. As compared with those in the sham-operated group, the optical density values of p-CX43 and LC3 positive cells in hippocampal CA3 regions of epilepsy group and epilepsy+solvent group were increased ( P<0.05). As compared with those in the epilepsy group and the epilepsy+solvent group, the optical density values of p-CX43 and LC3 positive cells in the hippocampal CA3 regions of the epilepsy+CBX group were significantly decreased ( P<0.05). Morris water maze test results showed that as compared with that in the sham-operated group, the escape latency in the epilepsy group and epilepsy+solvent group was significantly prolonged ( P<0.05); as compared with that in the epilepsy group and epilepsy+solvent group, the latency in the epilepsy+CBX group was significantly shortened ( P<0.05). Conclusion:CBX can weaken the neuronal autophagy and reduce the damage to cognitive function by inhibiting the p-Cx43 protein expression in the astrocytes of the hippocampal CA3 regions.