耐药性颞叶癫痫大鼠海马组织γ-氨基丁酸A、B受体表达观察

Expression of GABAA and GABAB in hippocampus of pharmacoresistant temporal lobe epilepsy rats

目的观察耐药性颞叶癫痫大鼠海马组织γ-氨基丁酸A(GABAA)受体、γ-氨基丁酸B(GABAB)受体表达的变化,以探讨二者在颞叶癫痫大鼠耐药机制中的作用。方法随机选取雄性SD大鼠60只,制作氯化锂-匹罗卡品大鼠癫痫模型,根据癫痫大鼠对抗癫痫药物苯妥英钠及苯巴比妥的反应分为耐药组、药物敏感组,选择8只正常SD大鼠作为对照组。处死各组动物,取出大脑海马组织,分别采用免疫组织化学法、蛋白质免疫印迹法检测海马组织GABAA、GABAB受体。结果免疫组织化学染色结果显示,耐药组大鼠海马组织GABAA、GABAB受体平均积分光密度(MOD)值分别为0.157±0.016、0.158±0.026,药物敏感组分别为0.262±0.016、0.263±0.027,对照组分别为0.294±0.040、0.307±0.032;耐药组、药物敏感组与对照组相比,P<0.05;耐药组、药物敏感组相比,P<0.05。蛋白质免疫印迹法检测结果显示,耐药组GABAA、GABAB受体累积积分光密度(IOD)值(代表GABAA、GABAB蛋白相对表达量)分别为0.121±0.029、0.071±0.016,药物敏感组分别为0.223±0.036、0.149±0.012,对照组分别为0.261±0.034、0.180±0.011,耐药组、药物敏感组与对照组相比,P<0.05;耐药组、药物敏感组相比,P<0.05。结论 GABAA、GABAB受体在耐药性颞叶癫痫大鼠海马组织中表达降低,二者可能与癫痫耐药发生有关。

Objective To observe the expression changes ofγ-aminobutyric acid receptor A(GABAA)andγ-aminobutyric acid receptor B(GABAB)in the hippocampus of pharmacoresistant temporal lobe epilepsy rats,and to explore their role in the mechanism of resistance in rats with temporal lobe epilepsy.Methods Sixty adult male SD rats were selected to establish the epilepsy models by pilocarpine introperitonial injection.The models of pharmacoresistant epilepsy were selected by their response to antiepileptic drugs phenobabital and phynitoin.The epileptic rats were divided into the pharmacosensitive epileptic group(PSE group,8 rats)and the pharmacoresistant epileptic group(PRE group,8 rats).Another normal rats were used as the normal control group(NRC group,8 rats).We executed the selected rats and removed the brain hippocampus.Immunohistochemistry and Western blotting were performed to assess GABAA and GABAB expression in the hippocampal tissues in the three groups.Results Immunohistochemistry showed that the mean optical density(MOD)of GABAA and GABAB in the hippocampi were 0.157±0.016 and 0.158±0.026 in the PRE group,0.262±0.016 and 0.263±0.027 in the PSE group,and 0.294±0.040 and 0.307±0.032 in the NCR group;significant difference was found between the PRE and PSE groups and the NCR group(P<0.05),and between the PRE group and PSE group(P<0.05).Western blotting showed that the integrated optical density(IOD)of GABAA and GABAB were 0.121±0.029 and 0.071±0.016 in the PRE group,0.223±0.036 and 0.149±0.012 in the PSE group,and 0.261±0.034 and 0.180±0.011 in the NCR group;significant difference was found between the PRE and PSE groups and the NCR group(P<0.05),and between the PRE group and PSE group(P<0.05).Conclusion The expression of GABAA and GABAB in the pharmacoresistant epileptic rats decreases,and both of them may be related to the epileptogenesis of pharmacoresistance.