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1.
目的:探讨异氟烷预处理对电磁脉冲辐射所致脑损伤的保护作用。方法:选取成年雄性SD大鼠48只,采用随机数字表法,将其随机分为4组(n=12),分别为:假辐照组(CON组)、电磁辐照组(EMP组)、异氟烷预处理组(IP组)和异氟烷预处理+电磁辐照组(IP+EMP组)。EMP组场强为400 KV/m,脉冲为200次,连续辐照3天;IP组吸入2.0%异氟醚2h;IP+EMP组吸入2.0%异氟醚2 h,24 h后制备EMP损伤模型。于辐照后24 h处死大鼠,每组随机抽取3只大鼠,取脑组织,采用ELISA法检测大鼠海马IL-6和TNF-α的表达变化;尼氏染色法观察大鼠海马区神经元的凋亡;采用Western blot法检测大鼠海马区BDNF蛋白的表达情况;采用免疫荧光法检测大鼠海马区BDNF细胞水平的表达。结果:与CON组比较,EMP组、IP组、IP+EMP组的IL-6和TNF-α的表达增高,尼氏小体减少,BDNF蛋白及细胞水平的表达均下调(P0.05);与EMP组比较,IP组和IP+EMP组IL-6和TNF-α的表达降低,尼氏小体增多,BDNF蛋白及细胞水平的表达上调(P0.05)。结论:异氟烷预处理可减轻电磁脉冲辐射所致脑损伤,其机制可能与减轻大鼠炎症反应有关。  相似文献   

2.
目的:探讨Homer-1a蛋白在异氟烷(Iso)预处理脑保护中的作用。方法:60只雄性SD大鼠(250~270g),随机分为三组:Sham组(n=20),仅分离血管不留置线栓;IR组(n=20)采用线栓法栓塞大脑中动脉致局灶性脑缺血模型,2h再灌注;IP组(n=20),接受1h的异氟烷预处理(2%异氟烷,98%氧),预处理后24h制作Mcao模型,分别于24h、48h、72h、7天后观察动物神经行为学改变。用Westernblot于24h、48h、72h、7天后对Homer-1a蛋白表达量进行分析。结果:24h时,IR组Homer-1a蛋白表达量低于Sham组(P〈0.05).IP组Homer—1a蛋白表达量明显高于Sham组(P〈0.01),IP组Homer-1a蛋白表达量高于IR组(P〈0.05);48h时,IP组Homer.1a蛋白表达量高于Sham组(P〈0.05),IR组Home〉1a蛋白表达量低于Sham组,IP组Home-1a蛋白表达量与IR组没有统计学意义;72h时,Sham组与IR组、IP组之间均无统计学意义;7天时,Sham组与IR组、IP组之间均无统计学意义。结论:在局灶性脑缺血中异氟烷预处理提高了Home-1a蛋白表达。  相似文献   

3.
目的 观察异氟烷单独或联合咪达唑仑对7日龄大鼠大脑caspase-3表达的影响.方法 7日龄SD大鼠39只,随机分为对照组(C组,n=13),异氟烷组(I组,n=13)和咪达唑仑联合异氟烷组(MI组,n=13).C组:腹腔注射0.9%生理盐水10ml/kg,吸入30%O2 6 h;I组:在37℃恒温并通入1.5%异氟烷的麻醉小室内维持麻醉6h ;MI组:腹腔注射咪达唑仑9 mg/kg后,随即置于37℃恒温并通入1.5%异氟烷的麻醉小室内维持麻醉6h.麻醉结束即刻每组取3只大鼠,行动脉血气分析.麻醉结束2h 采用Realtime-PCR方法检测皮质和海马组织Caspase-3 mRNA水平的变化;并用免疫组织化学SABC法检测大脑Active caspase-3阳性神经细胞的分布情况,计数阳性细胞.结果 ⑴ I组和MI组大鼠麻醉结束即刻动脉血气分析结果与C组比较差异无统计学意义(P>0.05).⑵ Realtime-PCR 结果显示,I组与MI组大鼠皮质和海马区Caspase-3 mRNA与对照组相比表达增多,且MI组与I组比较Caspase-3 mRNA表达增加(P<0.05).⑶免疫组化结果也显示:与对照组相比,I组与MI组大鼠在皮质、海马及丘脑部位Active caspase-3阳性神经细胞数量均明显增多 (P<0.05),而MI组与I组相比,在海马和丘脑部位Active caspase-3阳性神经细胞数量明显增多(P<0.05).结论 异氟烷麻醉能诱导脑发育高峰期大鼠重要脑区Caspase-3表达增加,联合应用咪达唑仑增加更明显;推测Caspase-3表达增加可能引起凋亡级联反应,导致神经细胞凋亡增加.  相似文献   

4.
目的:观察二十二碳六烯酸(DHA)是否通过抑制氧化应激反应减轻七氟烷所致神经元损伤。方法:HT22小鼠海马神经元分为Con组、DHA组和Sevo组和DHA+Sevo组,药物处理各组细胞24 h后,在倒置相差显微镜下拍照记录各组细胞形态改变,采用MTT法检测神经元存活情况,检测各组培养基中LDH, NO, SOD及MDA的含量。结果:CON组和DHA组细胞形态正常,Sevo组细胞皱缩,胞体破裂,正常形态消失,而DHA+Sevo组细胞形态基本正常,皱缩破裂的细胞较少;与CON组和DHA组相比,Sevo组HT22细胞存活率下降至CON组的25.79%,培养液中LDH的漏出量显著增加至CON组的400.15%,SOD活力下降至CON组的30.96%,培养液中NO及MDA的含量分别增加至CON组的507.62%和342.15%(P0.05);而与Sevo组相比,DHA+Sevo组HT22细胞存活率增加至CON组的75.68%,培养液中LDH的漏出量下降至CON组的175.68%,SOD活力增加至CON组的70.48%,培养液中NO及MDA的含量分别下降至CON组的355.80%和192.27%(P0.05)。结论:DHA通过抗氧化应激反应减轻七氟烷对HT22细胞的损伤。  相似文献   

5.
采用Aβ诱导建立海马神经元损伤模型,CCK-8检测神经元的活性,RT-PCR检测神经元凋亡相关基因Caspase-3 mRNA的表达,探讨了鼠尾草酸对Aβ所致海马神经元损伤的保护作用及其机制。结果显示,浓度在5~10μmol/L时,鼠尾草酸预处理能显著下调Aβ损伤导致的Caspase-3 mRNA表达的升高,增强神经元活力。表明鼠尾草酸预处理可以保护Aβ所致小鼠海马神经元的损伤,其机制可能与鼠尾草酸调控神经元凋亡相关基因caspase-3 mRNA的表达有关。  相似文献   

6.
镁离子对谷氨酸诱发的海马神经元损伤的保护作用   总被引:4,自引:0,他引:4  
目的 :探讨镁离子 (Mg2 )在 0 .1mmol/L谷氨酸诱发的海马神经元损伤中的作用。方法 :将神经元从新生SD大鼠海马中分离后培养 6~ 9d ,即随机分成三组 :A .单纯培养基 ;B .培养基 谷氨酸 ;C .培养基 Mg2 ,30min后再加入谷氨酸。结果 :①B组海马神经元存活率与A组相比显著地呈剂量依赖性降低。②与B组对照 ,C组加用低浓度的Mg2 可提高海马神经元的存活率。结论 :低浓度的Mg2 能保护谷氨酸诱发损伤的海马神经元  相似文献   

7.
目的观察体积调节性氯离子通道阻滞剂NPPB对低渗条件下神经元凋亡的影响。方法采用原代培养的大鼠海马神经元细胞,实验分为对照组(无低渗溶液处理)、低渗组、低渗加NPPB干预组;在不同时间点(10min、30min、60min),应用AnnexinⅤ/PI流式细胞检测以及免疫细胞荧光三标法(TUNEL/MAP-2/DAPI)检测各实验组神经元凋亡的情况。结果与对照组相比,神经元在低渗干预10min后凋亡细胞明显增多,60min时神经元的凋亡达到高峰(P0.01),而NPPB干预组在各时间点凋亡神经元相对低渗组明显下降(P0.01),较正常对照组增高。结论低渗条件可诱导体外培养海马神经元细胞凋亡,体积调节性氯离子通道阻滞剂NPPB可以显著降低低渗诱导的神经元凋亡,提示VRAC通道参与了低渗诱导的神经元凋亡。  相似文献   

8.
目的:探讨异氟烷对小鼠星形胶质细胞Sirt1和MAO-A基因表达的影响。方法:给予体外培养的新生小鼠原代星形胶质细胞不同浓度异氟烷处理,实验分为对照组和异氟烷处理组(0.5ISO、1.0ISO、1.5ISO),其中异氟烷组细胞分别给予0.5 MAC、1.0MAC和1.5 MAC三个浓度的异氟烷处理2小时,对照组给予O_2处理2小时,然后提取细胞RNA和蛋白检测Sirt1和MAO-A的mRNA和蛋白表达变化。结果:与对照组相比,异氟烷下调小鼠星形胶质细胞的Sirt1和MAO-A mRNA和蛋白水平,异氟烷浓度越大下调越明显。结论:异氟烷可抑制小鼠星形胶质细胞的Sirt1和MAO-A基因表达。  相似文献   

9.
目的:观察大鼠体表严重伤后海马神经元的病理变化,探讨CNTF对其保护作用。方法:SD大鼠侧脑室埋管,制成30%体表面积Ⅲ度烫伤模型,伤后3天,测定脑组织含水量,海马乳酸脱氢酶(LDH)和一氧化氮(NO)的含量,做病理切片,尼氏染色。结果:大鼠严重烫伤后,脑组织含水量增加,海马出现明显的病理变化,尼氏小体减少或消失,胞体肿胀,LDH和N煌含量增加,给予CNTF后,脑水肿、海马的病理变化有明显改善,并  相似文献   

10.
目的:探讨miR-34a在幼鼠海马神经元细胞增殖凋亡中的作用。方法:分离幼鼠海马神经元细胞,转染miR-34a抑制剂(miR-34a inhibitor)、抑制剂对照(inhibitor control)、miR-34a模拟物(miR-34a mimics)、模拟物对照(mimics control),RT-PCR检测细胞中miR-34a表达水平。MTT检测转染后细胞增殖情况。流式细胞仪检测细胞凋亡情况。Western blot检测细胞中Cleaved-caspase-3、Bcl-2、Bax的表达水平。结果:转染miR-34a inhibitor可以抑制miR-34a的表达,miR-34a mimics可以促进miR-34a的表达。miR-34a mimics对细胞增殖抑制率明显高于mimics control组(P0.05),miR-34a inhibitor组抑制率明显低于inhibitor control组(P0.05)。miR-34a inhibitor组神经元细胞凋亡率明显低于inhibitor control组(P0.05),miR-34a mimics组神经元细胞凋亡率明显高于mimics control组(P0.01),inhibitor control组和mimics control组神经元细胞凋亡率差异不显著(P0.05)。miR-34a inhibitor组Cleaved-caspase-3、Bax蛋白表达量低于inhibitor control组,差异显著(P0.05);miR-34a inhibitor组Bcl-2蛋白表达量高于inhibitor control组,差异显著(P0.05);miR-34a mimics组Cleaved-caspase-3、Bax蛋白表达量高于mimics control,差异显著(P0.05);miR-34a mimics组Bcl-2蛋白表达量低于mimics control,差异显著(P0.05)。结论:miR-34a抑制海马神经元细胞增殖,促进细胞凋亡,其作用机制可能与调控Cleaved-caspase-3、Bcl-2、Bax表达有关。  相似文献   

11.
Ginsenoside Rb1 is one of the main active principles in traditional herb ginseng and has been reported to have a wide variety of neuroprotective effects. Endoplasmic reticulum (ER) stress has been implicated in neurodegenerative diseases, so the present study aimed to observe the effects of ginsenoside Rb1 on ER stress signaling pathways in high glucose-treated hippocampal neurons. The results from MTT, TUNEL labeling and Annexin V-FITC/PI/Hoechst assays showed that incubating neurons with 50 mM high glucose for 72h decreased cell viability and increased the number of apoptotic cells whereas treating neurons with 1 μM Rb1 for 72h protected the neurons against high glucose-induced cell damage. Further molecular mechanism study demonstrated that Rb1 suppressed the activation of ER stress-associated proteins including protein kinase RNA (PKR)-like ER kinase (PERK) and C/EBP homology protein (CHOP) and downregulation of Bcl-2 induced by high glucose. Moreover, Rb1 inhibited both the elevation of intracellular reactive oxygen species (ROS) and the disruption of mitochondrial membrane potential induced by high glucose. In addition, the high glucose-induced cell apoptosis, activation of ER stress, ROS accumulation and mitochondrial dysfunction can also be attenuated by the inhibitor of ER stress 4-phenylbutyric acid (4-PBA) and anti-oxidant N-acetylcysteine(NAC). In conclusion, these results suggest that Rb1 may protect neurons against high glucose-induced cell injury through inhibiting CHOP signaling pathway as well as oxidative stress and mitochondrial dysfunction.  相似文献   

12.
目的:研究芝麻素对NMDA所致原代培养小鼠皮层神经元损伤的保护作用及其机制。方法:体外培养原代皮层神经元;免疫荧光染色鉴定细胞纯度;MTT法测定细胞存活率;Hoechst/PI双染色观察细胞凋亡的形态学变化;激光共聚焦显微镜技术观察钙成像,检测细胞内钙离子浓度变化;Western blot检测各组细胞中Bcl-2、Bax、NR2A、NR2B蛋白的表达。结果:NMDA(200μM)60分钟能使神经元细胞存活率显著下降,细胞凋亡百分比明显增加(P0.01),芝麻素(0.1μM)能提高细胞存活率,减少细胞凋亡(P0.01)。与NMDA组相比,芝麻素能抑制钙超载;降低Bax和NR2B蛋白表达;增加和Bcl-2蛋白表达(P0.01)。结论:芝麻素具有神经保护作用,这种作用可能与抑制钙超载、下调NMDA受体亚型NR2B的表达以及调节Bcl-2家族蛋白有关。  相似文献   

13.
Although the potent anti-parkinsonian action of the atypical D1-like receptor agonist SKF83959 has been attributed to the selective activation of phosphoinositol(PI)-linked D1 receptor, whereas the mechanism underlying its potent neuroprotective effect is not fully understood. In the present study, the actions of SKF83959 on neuronal membrane potential and neuronal excitability were investigated in CA1 pyramidal neurons of rat hippocampal slices. SKF83959 (10–100 µM) caused a concentration-dependent depolarization, associated with a reduction of input resistance in CA1 pyramidal neurons. The depolarization was blocked neither by antagonists for D1, D2, 5-HT2A/2C receptors and α1-adrenoceptor, nor by intracellular dialysis of GDP-β-S. However, the specific HCN channel blocker ZD7288 (10 µM) antagonized both the depolarization and reduction of input resistance caused by SKF83959. In voltage-clamp experiments, SKF83959 (10–100 µM) caused a concentration-dependent increase of Ih current in CA1 pyramidal neurons, which was independent of D1 receptor activation. Moreover, SKF83959 (50 µM) caused a 6 mV positive shift in the activation curve of Ih and significantly accelerated the activation of Ih current. In addition, SKF83959 also reduced the neuronal excitability of CA1 pyramidal neurons, which was manifested by the decrease in the number and amplitude of action potentials evoked by depolarizing currents, and by the increase of firing threshold and rhoebase current. The above results suggest that SKF83959 increased Ih current through a D1 receptor-independent mechanism, which led to the depolarization of hippocampal CA1 pyramidal neurons. These findings provide a novel mechanism for the drug''s neuroprotective effects, which may contributes to its therapeutic benefits in Parkinson''s disease.  相似文献   

14.
目的:通过观察甲基苯丙胺中毒后小鼠脑组织超微结构的改变,探讨脑组织超微结构改变与甲基苯丙胺神经毒性机制的关系。方法:将40只小鼠随机分为对照组和3组实验组(A,B,C)。A组给予MA(20mg/kg,ip,single)、B组给予MA(20mg/kg,8am,8pm,ip×2d)、C组给予MA(20mg/kg,8am,8pm,ip×4d),对照组给予等量生理盐水。用电镜观察前额叶皮质、海马、纹状体三个部位组织神经元胞体超微结构改变,并与空白对照组比较,结果进行统计学处理。结果:给予MA后,小鼠各脑区神经元胞体出现神经元固缩、变性、凋亡、坏死等超微病变。结论:MA可诱导神经细胞发生神经元固缩、变性、凋亡、坏死等超微病变,其变化程度随时间和药物蓄积有逐渐增加的趋势。  相似文献   

15.
目的:本实验研究灵芝孢子粉对戊四氮活化大鼠海马神经细胞caspase-9表达变化的影响,进一步探索灵芝孢子粉对癫痫大鼠脑保护的作用机制和癫痫与海马神经细胞凋亡调控基因之间的关系。方法:通过制备癫痫模型,RT-PCR和Western blotting检测正常对照组、癫痫模型组和灵芝孢子粉用药组caspase-9的表达。结果:癫痫模型组和灵芝孢子粉用药组caspase-9的表达较正常对照组均升高;其中癫痫模型组caspase-9的表达水平与对照组比较明显升高,灵芝孢子粉用药组caspase-9的表达水平与癫痫模型组比较明显降低,差异有统计学意义。结论:本研究结果证实,Caspase-9介导了癫痫大鼠神经细胞凋亡机制,说明灵芝孢子粉有效成份能充分作用于脑组织,可以调控caspase-9的表达,发挥抗凋亡的神经保护作用。  相似文献   

16.
目的:通过观察甲基苯丙胺中毒后小鼠脑组织超微结构的改变,探讨脑组织超微结构改变与甲基苯丙胺神经毒性机制的关系。方法:将40只小鼠随机分为对照组和3组实验组(A,B,C)。A组给予MA(20mg/kg,ip,single)、B组给予MA(20mg/kg,8am,8pm,ip×2d)、C组给予MA(20mg/kg,8am,8pm,ip×4d),对照组给予等量生理盐水。用电镜观察前额叶皮质、海马、纹状体三个部位组织神经元胞体超微结构改变,并与空白对照组比较,结果进行统计学处理。结果:给予MA后,小鼠各脑区神经元胞体出现神经元固缩、变性、凋亡、坏死等超微病变。结论:MA可诱导神经细胞发生神经元固缩、变性、凋亡、坏死等超微病变,其变化程度随时间和药物蓄积有逐渐增加的趋势。  相似文献   

17.
Lysophosphatidic Acid Induces Necrosis and Apoptosis in Hippocampal Neurons   总被引:11,自引:1,他引:10  
Abstract: A diverse body of evidence indicates a role for the lipid biomediator lysophosphatidic acid (LPA) in the CNS. This study identifies and characterizes the induction of neuronal death by LPA. Treatment of cultured hippocampal neurons from embryonic rat brains with 50 µ M LPA resulted in neuronal necrosis, as determined morphologically and by the release of lactate dehydrogenase. A concentration of LPA as low as 10 µ M led to the release of lactate dehydrogenase. In contrast, treatment of neurons with 0.1 or 1.0 µ M LPA resulted in apoptosis, as determined by chromatin condensation. In addition, neuronal death induced by 1 µ M LPA was characterized as apoptotic on the basis of terminal dUTP nick end-labeling (TUNEL) staining, externalization of phosphatidylserine, and protection against chromatin condensation, TUNEL staining, and phosphatidylserine externalization by treatment with N -benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone, a broad-spectrum inhibitor of caspases, i.e., members of the interleukin-1β converting enzyme family. Studies with antagonists of ionotropic glutamate receptors did not indicate a significant role for these receptors in apoptosis induced by 1 µ M LPA. LPA (1 µ M ) also induced a decrease in mitochondrial membrane potential. Moreover, pretreatment of neurons with cyclosporin A protected against the LPA-induced decrease in mitochondrial membrane potential and neuronal apoptosis. Thus, LPA, at pathophysiological levels, can induce neuronal apoptosis and could thereby participate in neurodegenerative disorders.  相似文献   

18.
Prostaglandin H synthase exerts not only cyclooxygenase activity but also peroxidase activity. The latter activity of the enzyme is thought to couple with oxidation of dopamine to dopamine quinone. Therefore, it has been proposed that cyclooxygenase inhibitors could suppress dopamine quinone formation. In the present study, we examined effects of various cyclooxygenase inhibitors against excess methyl L-3,4-dihydroxyphenylalanine (L-DOPA)-induced quinoprotein (protein-bound quinone) formation and neurotoxicity using dopaminergic CATH.a cells. The treatment with aspirin inhibited excess methyl L-DOPA-induced quinoprotein formation and cell death. However, acetaminophen did not show protective effects, and indomethacin and meloxicam rather aggravated these methyl L-DOPA-induced changes. Aspirin and indomethacin did not affect the level of glutathione that exerts quenching dopamine quinone in dopaminergic cells. In contrast with inhibiting effects of higher dose in the previous reports, relatively lower dose of aspirin that affected methyl L-DOPA-induced quinoprotein formation and cell death failed to prevent cyclooxygenase-induced dopamine chrome generation in cell-free system. Furthermore, aspirin but not acetaminophen or meloxicam showed direct dopamine quinone-scavenging effects in dopamine-semiquinone generating systems. The present results suggest that cyclooxygenase shows little contribution to dopamine oxidation in dopaminergic cells and that protective effects of aspirin against methyl L-DOPA-induced dopamine quinone neurotoxicity are based on its cyclooxygenase-independent property.  相似文献   

19.
(1) Fluctuations of the membrane potential states are essential for the brain functions from the response of individual neurons to the cognitive function of the brain. It has been reported in slice preparations that the action potential duration is dependent on the membrane potential states. (2) In order to examine whether dependence of action potential duration on the membrane potential could happen in isolated individual neurons that have no network connections, we studied the membrane potential dependence of the action potential duration by artificially setting the membrane potentials to different states in individual cultured rat hippocampal neurons using patch-clamp technique. (3) We showed that the action potential of individual neurons generated from depolarized membrane potentials had broader durations than those generated from hyperpolarized membrane potentials. (4) Furthermore, the membrane potential dependence of the action potential duration was significantly reduced in the presence of voltage-gated K+ channel blockers, TEA, and 4-AP, suggesting involvement of both delayed rectifier I K and transient I A current in the membrane potential dependence of the action potential duration. (5) These results indicated that the dependence of action potential duration on the membrane potential states could be an intrinsic property of individual neurons. Bo Gong and Mingna Liu contributed equally to this work.  相似文献   

20.
目的:建立新生大鼠吸入麻醉模型并探讨吸入麻醉药异氟醚对其海马凋亡的影响。方法:Penlon Prima SP麻醉机、异氟醚挥发罐及自制带进出气口的麻醉小室。共55只7日龄的SD大鼠用于实验。将其中35只大鼠随机分为7组(n=5)。实验组(Ⅰ-Ⅵ组)异氟醚挥发罐刻度分别为0.125%,0.25%,0.5%,1%,1.5%,2%;新生大鼠置于自制密封麻醉小室内,分别通入含上述异氟醚浓度的混合气体。对照组(第Ⅶ组)给予未混合异氟醚的30%的氧气。将小室安放于37℃恒温箱内。调节气体流量2L/min。实验组于通入气体5,10,15,30,90,180,360 min(T1-7)时于小室出口处抽取10mL气体,采用气相色谱法测定麻醉小室内异氟醚浓度。于通入气体360 min(T7)自新生大鼠左心室采血行血气分析;另取SD大鼠20只,随机分为对照组(C组,n=10),1.5%异氟醚组(I组,n=10),按上述方法建立异氟醚吸入麻醉模型,麻醉结束后2h处死大鼠,采用免疫组织化学法观察C组和I组大鼠大脑海马区Active caspase-3的表达。结果:①麻醉小室出口异氟醚浓度(Y)与麻醉机挥发罐异氟醚浓度(X)的直线回归方程为Y=1.5472X-0.0575(r=0.9993)。②血气分析结果显示:Ⅰ-Ⅵ组与Ⅶ组血气分析组间差异无统计学意义(P0.05)。③免疫组化结果显示:与C组相比,I组大鼠海马Active caspase-3明显增加,差异有统计学意义(P0.05)。结论:通过麻醉机、异氟醚挥发罐及自制密封带进出气口的麻醉小室成功建立了新生大鼠异氟醚麻醉模型;为进一步研究异氟醚及相关吸入麻醉药对突触发生期的神经毒性提供了实验基础。  相似文献   

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