Orexin受体拮抗剂对睡眠剥夺的戊四氮致(癎)大鼠癫(癎)发作及脑组织病理学变化的影响

摘要

Objective To investigate the effects of orexin-1 rceptor (OX1R) and orexin-2 rceptor (0X2R) antagonists on seizure and changes of brain tissue pathology in pentylenetetrazol ( PTZ) induced epileptic rats following sleep deprivation ( SD) . Methods Forty-eight male Wistar rats were randomly divided into normal control (NC) group,PTZ group,SD + PTZ (SD) group,SD + PTZ + dimethylsulfoxide (DMSO) group, SD+PTZ + OX1R antagonist SB334867 (SB) group and SD +PTZ + 0X2R antagonist TCS 0X229 (TCS) group. SD was made by the modified multiplate method. Before and after 48 h of SD, the DMSO, SB or TCS was injected in rate paracele in corresponding group respectively. After SD 72 h, the PTZ (50 mg/kg) was intraperitoneal injectied to each rat to cause seizure. The latency,duration, grade score of seizures and mortality in each group were observed. In addition, hippocampus pathology change ( stained with HE) and proliferation cells ( BrdU signed, immuno fluorescence method) were observed. Results ( 1 ) Compared with PTZ group, in SD group and DMSO group, the seizure latency were significantly shorter; the duration and grade score of seizure, and mortality were significantly increased ( all P < 0. 001). The neuron damage in hippocampus CA3 region were more serious and the number of BrdU positive-cells in the hippocampus hilus and the subgranular zone ( SGZ ) were significantly increased ( P < 0. 001 ). The Difference between SD group and DMSO group was no statistical significance. (2) Compared with SD group, in SB group and TCS group, the seizures latency were significantly longer; the duration and grade score of seizure, and mortality were significantly decreased (all P < 0. 05 ). The neuron damage in hippocampus CA3 region were slight, the number of BrdU positive-cells in the hippocampus hilus and the SGZ were significantly decreased ( all P <0. 05) ; and which in TCS group were more remarkable ( P < 0. 05 - 0.01). Conclusions The orexin receptor antagonists, especially OX2R antagonist can reduce the adverse effect of SD on the PTZ-induced seizures by reducing the neuronal cell damage in the hippocampus CA3 region and inhibiting cellproliferation in the dentate gyrus.%目的 探讨orexin-1受体(OX1R)和orexin-2受体(OX2R)拮抗剂对睡眠剥夺(SD)的戊四氮(PTZ)致(癎)大鼠癫(癎)发作及脑组织病理学变化的影响.方法 雄性Wistar大鼠48只,随机分为正常对照(NC)组、PTZ组、SD+ PTZ( SD)组、SD+ PTZ+二甲基亚砜(DMSO)组、SD+ PTZ+ OX1R拮抗剂SB334867(SB)组和SD+ PTZ+ OX2R拮抗剂TCS OX229 (TCS)组.采用改良多平台SD法,SD前及SD 48 h分别给予相应组大鼠侧脑室注射DMSO、SB或TCS.SD 72 h给予各组腹腔注射PTZ 50 mg/kg诱导癫(癎)发作；观察各组大鼠癫(癎)发作的潜伏期、发作等级评分、发作持续时间及死亡率；应用常规染色法观察海马的病理学变化,免疫荧光法(BrdU标记)观察神经细胞增殖的变化.结果 (1)与PTZ组比较,SD组及DMSO组(癎)性发作的潜伏期明显缩短,发作等级评分、持续时间及死亡率明显增加(均P ＜0.001),海马CA3区神经元损害加重,海马齿状回门区和颗粒细胞下层BrdU阳性细胞数显著增多(P＜0.001)；SD组与DMSO组间差异无统计学意义.(2)与SD组比较,SB组和TCS组大鼠(癎)性发作的潜伏期明显延长,发作等级评分、持续时间及死亡率明显下降(均P＜0.05),海马CA3区神经元损害明显减轻,齿状回门区和颗粒下层BrdU阳性细胞数减少(均P ＜0.05)；TCS组的变化较SB组更显著(P＜0.05 ～0.01).结论 Orexin受体拮抗剂尤其是OX2R拮抗剂可通过减轻海马CA3区神经元的损害和抑制齿状回区细胞增殖减轻SD对PTZ诱导癫(癎)发作的不利影响.