柴胡疏肝汤对戊四氮致痫大鼠海马及额叶皮质c-fos表达的影响

目的 观察柴胡疏肝汤对戊四氮致痫大鼠海马及额叶皮质c-fos表达的影响.方法 选取经戊四氮诱导制作的癫痫模型大鼠48只,按随机数字表法分成6组:癫痫模型组、德巴金组、定痫丸组、柴胡疏肝汤低剂量组、柴胡疏肝汤中剂量组和柴胡疏肝汤高剂量组,每组各8只;另设正常对照组8只.正常对照组和癫痫模型组常规饲养,其他各组给予药物德巴金,定痫丸,低、中、高剂量柴胡疏肝汤处理,均连续灌胃治疗5周.免疫组化染色检测各组大鼠海马及额叶皮质c-fos的表达情况.结果 戊四氮致痫后大鼠海马及额叶皮质c-fos表达明显增强,而应用中、高剂量的柴胡疏肝汤,德巴金和定痫丸治疗后,大鼠海马及额叶皮质c-fos表达均明显减弱,与癫痫模型组比较差异均有统计学意义(P<0.05),而柴胡疏肝汤低剂量组大鼠海马及额叶皮质c-fos表达无明显减弱.结论 柴胡疏肝汤的抗癫痫作用机制可能与其含有柴胡皂甙及其他多种有效的抗癫痫成份多靶点干预海马及额叶皮质c-fos表达水平有关.

Abstract：

Objective To observe the effect of chaihushugantang on the expression of c-fos in the hippocampus and frontal lobe cortex of pentylenetetrazole (PTZ)-induced epileptic rats. Methods Forty-eight PTZ-induced epileptic rats were randomly divided into 6 groups: epileptic model group,Valproate treatment group, Dingxianwan treatment group, and lower-dose, medium-dose and high-dose chaihushugantang treatment groups (n=8). Normal control group was also employed (n=8). The epileptic rats in the normal control group and epileptic model group were fed normally. Rats of the treatment groups were performed intragastric administration of medicines (Valproate, Dingxianwan and chaihushugantang) for 5 weeks in succession respectively. The expression of c-fos in the hippocampus and frontal lobe cortex of all the rats was observed. Results The expression of c-fos in the hippocampus and frontal lobe cortex of rats in the epileptic model group was significantly increased, while the c-fos expression in the hippocampus and the frontal lobe cortex of rats in the medium-dose and high-dose chaihushugantang treatment groups and Valproate treatment group and Dingxianwan treatment group was significantly decreased as compared with that in epileptic model group (P<0.05). But the c-fos expression in the hippocampus and the frontal lobe cortex of rats in the low-dose chaihushugantang treatment group showed no obvious decrease. Conclusion Chaihushugantang has good antiepileptic effect, might through affecting the c-fos expression in the epileptic rats. The antiepileptic mechanism of chaihushugantang can be related to saikosaponins and other antiepileptic constituents in it.     

戊四氮致痫对大鼠海马星形胶质细胞的影响

目的　探讨戊四氮（ＰＴＺ）致痫对大鼠海马星形胶质细胞的影响。方法　应用免疫组织化学方法观察ＰＴＺ致痫后大鼠海马内胶原纤维酸性蛋白（ＧＦＡＰ）变化的特点,同时观察了不同强度的痫性发作与ＧＦＡＰ改变的关系。结果　ＧＦＡＰ改变于ＰＴＺ致痫后１２ｈ 开始,２４ｈ 达到高峰,７２ｈ 已开始回落,并且痫性发作的强度与ＧＦＡＰ改变有一定的联系。结论　癫痫与星形细胞之间确有一定联系。     

戊四氮致痫大鼠脑内热休克蛋白70的表达

目的：探讨热休克蛋白70（HSP70）在癫痫大鼠脑内的表达情况及其意义。方法：采用戊四氮致痫模型。应用免疫组织化学及常规清理检查的方法进行研究。结果：在正常大鼠脑内未见HSP70免疫反应（IR）阳性细胞,成四氮致痫12小时后脑内开始出现HSP70IR阳性细胞,24小对IR达高峰．3天后开始下降．7天后消失。HSP70主要在边缘系统（尤其是海马的CA1、CA3、CA4区）、大脑皮质（尤其是颞叶皮质,梨状皮质）等区域表达。同时常规病理检查发现,上述区域散在出现受损的异常神经元。结论：癫痫发作可诱导HSP70在大鼠脑内广泛表达。HSP70表达可作为神经元受损的一个早期指标。     

氯喹对戊四氮致痫大鼠GFAP、PCNA及Cyclin D1变化的影响

目的 观察氯喹对戊四氮致痫大鼠皮质和海马星形胶质细胞GFAP、PCNA及Cyclin D1表达的影响．探讨氯喹在癫痫发生发展过程中的作用。方法 用免疫组化检测大鼠皮质和海马GFAP和PCNA的变化，用Westernblot检测CyclinD1含量的变化。结果 对照组无痫样发作，戊四氮致痫组有重型的痫样发作（Ⅲ～V级），氯喹干预组有轻型的痫样发作（Ⅰ～Ⅲ级）（P〈0．05）；戊四氮致痫组脑电记录呈频发高幅的痫样波，氯喹干预组痫样波幅低且缓。GFAP和PCNA在戊四氮致痫组表达强，以海马为著，与对照组比较差异有显著性意义（P〈0．05），氯喹干预组与对照组比较差异无显著性（P〉0．05）；Cyclin D1在戊四氮致痫组的皮质和海马的含量与对照组比较差异有显著性意义（P〈0．05），氯喹干预组与对照组比较差异无显著性意义（P〉0．05）。结论 氯喹通过抑制胶质细胞的增生和GFAP的表达，影响致痫大鼠痫样发作的发生和发展。     

胍丁胺对戊四氮诱导慢性癫癎大鼠的保护作用和海马星形胶质细胞表达的影响

目的:探讨不同剂量胍丁胺对戊四氮诱导的慢性癫癎大鼠模型的保护作用及对海马区星形胶质细胞表达的影响。方法:连续28 d腹腔注射戊四氮35 mg.kg-1建立大鼠慢性癫癎模型。不同剂量胍丁胺(20、40、80 mg.kg-1)进行干预。观察大鼠癫癎发作行为学及海马的形态学变化,检测海马星形胶质细胞的表达。结果:胍丁胺40、80 mg.kg-1可降低癫癎发作的日均等级评分,减少海马神经元丢失及星形胶质细胞增生。结论:胍丁胺40、80 mg.kg-1可抑制慢性癫癎大鼠发作,降低惊厥发作后海马星形胶质细胞的异常增生及神经元损伤。     

戊四氮致痫大鼠海马GSK-3β表达与苔藓纤维出芽关系研究

目的观察戊四氮(PTZ)致痫大鼠海马各区糖原合成酶激酶-3β(GSK-3β)蛋白及其mRNA表达和苔藓纤维出芽(MFS)情况,探讨GSK-3β在癫痫发病机制中的作用。方法SD雄性成年大鼠120只,随机分为实验组和对照组;实验组分为PTZ第1次注射后3d、1w、2w、4w、6w共5个亚组,每亚组12只。对照组同样随机分为5个亚组,每亚组12只,与实验组各时间点对应。以上各亚组再分2个小组,每小组6只大鼠,分别进行(1)GSK-3β的免疫组化和原位杂交染色并测定其相应的光密度值;(2)Timm染色并评分。结果实验组大鼠海马各区GSK-3β蛋白及其mRNA表达在点燃过程中逐渐增多,点燃后表达逐渐下调到正常对照组水平,在点燃前后除6w组外GSK-3β表达与对照组相应时间点比较差异有统计学意义(P<0.05);实验组CA3区在点燃前可见1~4级MFS,点燃后可见4~5级MFS;癫痫点燃过程中CA3区GSK-3β表达与MFS评分有线性正相关关系。结论GSK-3β在海马表达变化可能在苔藓纤维出芽的过程中起促进作用,从而促进癫痫的发生。     

绿茶多酚对戊四氮致痫大鼠海马XIAP和Caspase-3表达的影响

目的 探讨绿茶多酚(Green tea polyphenols,GTPs)对癫痫大鼠海马中XIAP、caspase-3表达的影响.方法 将雄性Wistar大鼠随机分为正常对照组(NS组)、癫痫组(PTZ组)和绿茶多酚组(GTPs组).依据Racine分级标准观察各组动物行为学表现,用HE染色观察大鼠海马神经元损伤情况,Western Blot方法测定各组大鼠海马组织中XIAP及caspase-3蛋白表达变化.结果 PTZ组:大鼠海马XIAP表达水平(0.23±0.02)较NS组(0.47±0.05)明显降低(P＜0.05);caspase-3蛋白(0.63±0.12)较NS组(0.24±0.07)明显升高(P＜0.05).与PTZ组比较,GTPs组大鼠海马XIAP表达(0.53±0.10)显著升高(P＜0.05);caspase-3表达(0.30±0.09)显著降低(P＜0.05).结论 癫痫可导致海马组织中抗凋亡蛋白XIAP表达下降,凋亡执行蛋白caspase-3表达增加;而GTPs则能够上调XIAP表达,降低caspase-3的表达,推测GTPs可能通过抗凋亡途径来发挥癫痫后的神经保护作用.     

戊四氮致痫大鼠不同脑区神经肽Y的表达及意义

目的研究神经肽Y(neuropeptideY,NPY)在戊四氮(pentylenetetrazol,PTZ)致痫大鼠不同脑区中的变化,以探讨NPY与癫痫的关系。方法清洁级近交系雄性SD大鼠50只,分为对照组(A组,n=10)及实验组(40只)。实验组按体重50mg/kg经腹腔注射PTZ1次,对照组腹腔注射同等容量的生理盐水。根据癫痫发作分级,0~1级7只为B组,立即取脑;2级以上发作33只,随机于癫痫发作后0(C组,n=10)、6(D组,n=11)、24(E组,n=10)、72h(F组,n=2)取脑。采用放射免疫方法动态观察脑组织中海马、中脑、纹状体和额叶中NPY的改变;SP免疫组化染色法染色,观察各组大鼠海马CA1区NPY的表达。结果B组中脑、纹状体及额叶NPY含量较A组升高(P<005),而两组间海马NPY含量差异无显著性;癫痫发作组(C组、D组、E组)各部位NPY含量均明显高于A组。动态观察结果显示,癫痫发作后在中脑、海马、纹状体和额叶的NPY含量明显增高随后呈逐步下降,在癫痫发作后24h其含量与未发生惊厥的B组NPY含量差异无显著性(P>005);免疫组化染色显示癫痫大发作后海马NPY的表达明显增加,但随着时间的推移而降低。结论NPY与大鼠癫痫的发生、发展有密切关系。     

戊四氮致痫大鼠脑P53蛋白表达与神经细胞凋亡关系的研究

目的探讨戊四氮诱导癫痫发作大鼠脑P53蛋白表达与神经细胞凋亡的关系.方法采用戊四氮诱导癫痫发作大鼠模型,以原位末端标记(TUNEL)法和免疫组织化学方法分别检测大鼠脑海马CA1区神经细胞凋亡及P53蛋白表达的动态变化.结果戊四氮致痫后6h海马周白质出现P53蛋白较弥散的表达,12h时海马CA1区可见少量锥体细胞凋亡,细胞核出现P53蛋白的微弱表达,24h时凋亡的锥体细胞数明显升高,P53蛋白表达开始增加,至48h两者同时达高峰(P＜0.001),此后开始下降.结论P53是调节戊四氮诱导癫痫发作大鼠脑神经细胞凋亡的重要分子之一.     

戊四氮致惊厥大鼠海马神经元Cyclin D1表达改变和意义

目的 探讨戊四氮致惊厥大鼠海马细胞周期素Cyclin D1与神经细胞凋亡的关系。方法 利用寡核苷酸探针原位组织杂交技术观察各组海马Cyclin D1 mRNA的表达水平。同时采用TUNEL原位末端标记方法观察神经元凋亡。结果 戊四氮致惊厥后6h,大鼠海马内Cyclin D1 mRNA表达开始增强,12h达到高峰,24h开始回落。同时,观察到戊四氮致惊厥大鼠海马神经元凋亡数量有类似改变。结论 Cyclin D1 mRNA表达水平的增高可能表明戊四氮致惊厥大鼠海马神经元重新进入细胞周期,可能与神经细胞凋亡有关。     

Upregulation of adenosine kinase in astrocytes in experimental and human temporal lobe epilepsy

Purpose: Adenosine kinase (ADK) represents the key metabolic enzyme for the regulation of extracellular adenosine levels in the brain. In adult brain, ADK is primarily present in astrocytes. Several lines of experimental evidence support a critical role of ADK in different types of brain injury associated with astrogliosis, which is also a prominent morphologic feature of temporal lobe epilepsy (TLE). We hypothesized that dysregulation of ADK is an ubiquitous pathologic hallmark of TLE. Methods: Using immunocytochemistry and Western blot analysis, we investigated ADK protein expression in a rat model of TLE during epileptogenesis and the chronic epileptic phase and compared those findings with tissue resected from TLE patients with mesial temporal sclerosis (MTS). Key Findings: In rat control hippocampus and cortex, a low baseline expression of ADK was found with mainly nuclear localization. One week after the electrical induction of status epilepticus (SE), prominent up‐regulation of ADK became evident in astrocytes with a characteristic cytoplasmic localization. This increase in ADK persisted at least for 3–4 months after SE in rats developing a progressive form of epilepsy. In line with the findings from the rat model, expression of astrocytic ADK was also found to be increased in the hippocampus and temporal cortex of patients with TLE. In addition, in vitro experiments in human astrocyte cultures showed that ADK expression was increased by several proinflammatory molecules (interleukin‐1β and lipopolysaccharide). Significance: These results suggest that dysregulation of ADK in astrocytes is a common pathologic hallmark of TLE. Moreover, in vitro data suggest the existence of an additional layer of modulatory crosstalk between the astrocyte‐based adenosine cycle and inflammation. Whether this interaction also can play a role in vivo needs to be further investigated.     

托吡酯对戊四氮致癫癎大鼠海马AQP4表达水平的影响

目的探讨托吡酯对戊四氮致癫癎大鼠海马AQP4表达水平的影响。方法将30只Wistar大鼠随机分为戊四氮致癫癎组、托吡酯干预组和正常对照组，每组各10只；癫癎模型点燃后在不同时相点灌注取材，通过HE染色观察大鼠海马神经元的变化，并应用免疫组化法检测大鼠海马AQP4表达水平。结果HE染色显示托吡酯干预组神经元变性和坏死较戊四氮致癫癎组明显减轻；免疫组化显示戊四氮致癫癎组在致癫癎后12hAQP4的表达显著增强，致癫癎后24h达高峰，托吡酯干预组在致癫癎后12h～36h各时相点AQP4表达水平均分别低于戊四氮致癫癎组相应时间点（P〈0．05）。结论托吡酯通过下调大鼠海马AQP4的表达可能参与了对大鼠海马神经元的保护过程。     

匹罗卡品致疒间大鼠海马GAP-43与TrkB基因表达及其意义

目的探讨生长相关蛋白(GAP-43)和脑源性神经营养因子(BDNF)受体TrkB基因在匹罗卡品致疒间大鼠海马的表达及其意义.方法应用原位杂交组织化学方法研究匹罗卡品(PILO)致疒间大鼠海马GAP-43及TrkB mRNA表达的变化.结果匹罗卡品致癫疒间持续状态后3～6小时,海马齿状回颗粒细胞、CA3区及CA1区锥体细胞层TrkB mRNA表达显著高于对照组(P<0.01或0.05);在慢性期第7～30天,呈现第2次表达增强.致疒间后6～12小时,正常状态下并不表达GAP-43的大鼠海马颗粒细胞其GAP-43 mRNA表达较对照组显著增高(P<0.01),24小时～7天表达减少,在癫疒间慢性期表达再次高于对照组.结论 GAP-43及TrkB是颞叶癫疒间病理基础--海马苔藓纤维出芽的重要分子机制;BDNF对苔藓纤维的作用部分是通过GAP-43实现的.     

去势对戊四氮点燃大鼠癫痫模型的行为学表现

目的 研究去势对戊四氮点燃大鼠癫痫模型行为学表现的影响.方法 采用戊四氮腹腔注射制作癫痫大鼠模型,对照研究去势大鼠同正常大鼠的潜伏期及持续时间等行为学表现.结果 大鼠癫痫模型全部点燃,去势组平均潜伏期(8.09±0.89) min((-x)±SD)长于非去势组的(3.94±0.65) min((-x)±SD).发作时间也有所缩短,去势组(19.16 ±3.06) min((-x)±SD)略短于非去势组的(26.37±2.90) min((-x)±SD) (P ＜0.05).非去势组点燃时间明显短于去势组,非去势组平均点燃时间(20.83±6.15) d((-x)±s),而去势组平均点燃时间(24.6±5.64) d((-x)±SD).结论 戊四氮点燃大鼠致痫模型是一种成熟的、较为安全的癫痫模型.去势后,SD雄鼠较正常非去势SD雄鼠相比致痫潜伏期延长、持续时间缩短、发作频率及程度减轻,点燃时间也明显长于正常SD雄鼠.     

马桑内酯致痫大鼠大脑皮层、海马NMDA受体亚单位1(NMDAR1)mRNA表达的变化

目的　探讨癫痫发病的分子机制。方法　采用原位杂交技术 ,研究了马桑内酯致痫大鼠大脑皮层、海马 N-甲基 - D-天门冬氨酸受体亚单位 1(NMDAR1) m RNA表达的变化。结果　马桑内酶致痫大鼠顶叶大脑皮层及海马齿状回 NMDAR1m RNA水平显著高于生理盐水对照组 (P<0 .0 1,P<0 .0 5 )。结论　马桑内酯上调脑组织内NMDAR1m RNA水平 ,此可能是其致痫及惊厥易感性增加的分子机制之一     

Modulation of adenosine release from rat spinal cord by adenosine deaminase and adenosine kinase inhibitors

Adenosine, a modulator of pain processing in the spinal cord, is metabolized by adenosine kinase and adenosine deaminase. In this study we determined which of these mechanisms is more important for the regulation of endogenous adenosine levels in the rat spinal cord. The effects of the adenosine kinase inhibitors, 5′-deoxyadenosine (NH₂dAD) and iodotubercidin (IOT), and the adenosine deaminase inhibitor, 2′-deoxycoformycin (DCF), on adenosine release in a spinal cord superfusion model were studied. DCF markedly increased basal adenosine levels detected in perfusates and was more potent than NH₂dAD and IOT in this regard. Coadministration of DCF with NH₂dAD produced an enhanced effect compared to the inhibitors alone. NH₂dAD, but not DCF, potentiated morphine-evoked adenosine release. These results suggest that adenosine deaminase may be the predominant pathway for adenosine metabolism in this experimental model.     

Indomethacin modulates ischemia-evoked release of glutamate and adenosine from the rat cerebral cortex

The effects of indomethacin (10 mg/kg) on the release of the transmitter amino acids, glutamate, aspartate, GABA, and of the purines, adenosine and inosine, from the cerebral cortex was studied in a four-vessel occlusion rat model of cerebral ischemia/reperfusion. In comparison with the control group, indomethacin significantly attenuated the ischemia-evoked release of glutamate and aspartate, but not of GABA. Adenosine levels in the cortical superfusates were significantly elevated following indomethacin administration. As indomethacin is a potent inhibitor of adenosine uptake, these results suggest that, by blocking adenosine uptake, indomethacin could elevate extracellular adenosine levels and depress glutamate and asparte efflux as a consequence of the activation of adenosine A₁ receptors.     

Astrocyte stellation induced by tyrosine kinase inhibitors in culture

To understand the role of tyrosine kinases in regulation of astrocyte morphology, we investigated the effects of tyrosine kinase inhibitors on morphology of cultured rat cortical astrocytes. Cultured astrocytes exhibited flattened, polygonal morphology in the absence of stimulation, but changed into process-bearing stellate cells in the presence of the tyrosine kinase inhibitor genistein (3-100 microM). Genistein-induced astrocyte stellation was abolished by treatment with colchicine or paclitaxel, indicating the involvement of cytoskeletal elements. The effect of genistein was mimicked by another tyrosine kinase inhibitor herbimycin A, but not by daidzein, an inactive analog of genistein. These results suggest that tyrosine kinases are in an activated state in the absence of stimuli and contribute to the maintenance of polygonal morphology of cultured astrocytes.