黄连解毒汤有效部位对培养大鼠皮层神经元谷氨酸损伤的保护作用

目的观察黄连解毒汤有效部位对培养神经细胞谷氨酸兴奋毒性的保护作用.方法体外培养新生大鼠皮层神经细胞,加入谷氨酸观察谷氨酸对神经细胞的兴奋毒性及黄连解毒汤有效部位的保护作用.结果黄连解毒汤有效部位305 mg/kg能明显增高模型细胞的活性;610、305、153 mg/kg能显著降低模型细胞乳酸脱氢酶(LDH)漏出率,降低MDA生成;305、153 mg/kg可减少NO生成,610 mg/kg还可提高SOD活性.结论黄连解毒汤有效部位对培养神经细胞谷氨酸兴奋毒性具有显著的保护作用,其机制可能与降低NO含量、抗过氧化作用有关.     

不同浓度七氟醚预处理对大鼠海马神经元缺氧复氧时细胞凋亡的影响及线粒体ATP敏感型钾通道在其中的作用

目的 探讨不同浓度七氟醚预处理对大鼠海马神经元缺氧复氧时细胞凋亡的影响及线粒体ATP敏感型钾通道(mito-KATP通道)在其中的作用.方法 新生(出生＜24 h)SD大鼠,雌雄不拘,体重5～6 g,原代培养海马神经元,接种于培养孔或培养皿中,采用随机数字表法,将其随机分为7组,每组48孔和12皿,正常对照组(C组):不予任何处理;缺氧复氧组(HR组):缺氧4 h复氧24 h;6%七氟醚预处理组(S1 组)、4%七氟醚预处理组(S2 组)、2%七氟醚预处理组(S3 组):分别经6%、4%、2%七氟醚预处理后行缺氧复氧;5-羟葵酸100 μmol/L预处理组(5-HD组):经mito-KATP通道阻断剂5-羟葵酸(终浓度100 μmol/L)预处理后进行缺氧复氧;5-羟葵酸100 μmol/L+6%七氟醚预处理组(5-HD+S组):同时行5-羟葵酸和6%七氟醚预处理后进行缺氧复氧.各组以上处理结束后,测定神经元活力、凋亡率、Bcl-2和Bax蛋白的表达水平.结果 与C组比较,其余6组海马神经元活力降低,细胞凋亡率升高,Bcl-2和Bax蛋白表达上调(P＜0.01);与HR组比较,S1组～S3组海马神经元活力增强,细胞凋亡率降低,Bcl-2蛋白表达上调,Bax蛋白表达下调(P＜0.01),5-HD组和5-HD+S组上述指标比较差异无统计学意义(P＞0.05);与S1组比较,S2组、S3组和5-HD+S组海马神经元活力降低,细胞凋亡率升高,Bcl-2蛋白表达下调,Bax蛋白表达上调(P＜0.01);与S2组比较,S3组海马神经元活力降低,细胞凋亡率升高,Bcl-2蛋白表达下调,Bax蛋白表达上调(P＜0.01).结论 七氟醚预处理可抑制大鼠海马神经元缺氧复氧时细胞凋亡,从而减轻神经元损伤,且呈浓度依赖性,机制可能与开放神经元mito-KATP通道,上调Bcl-2蛋白表达,下调Bax蛋白表达有关.

Abstract：

Objective To investigate the effect of preconditioning with different concentrations of sevoflurane on hypoxia-reoxygenation(H/R)-induced apoptosis in rat hippocampal neurons and the role of mitochondrial KATP(mito-KATP)channels.Methods Primary cultured hippocampal neurons isolated from newborn SD rats(＜24h)of both sexes,weighing 5-6 g,were randomly divided into 7 groups with 48 wells and 12 dishes in each one:control group(C group),H/R group,preconditioning with 6%,4%and 2% sevoflurane groups(S1-3 groups),5-hydroxydecanoate(5-HD,mito-KATP channel blocker)100 μmol/L preconditioning group(5-HD group)and preconditioning with 5-HD 100 μmol/L+6% sevoflurane group(5-HD+S group).The neurons were exposed to 4 h hypoxia followed by 24 h reoxygenation. In S1-3 groups, preconditioning was performed with 6% , 4% and 2% sevoflurane respectively before H/R. In 5-HD group, preconditioning was performed with 5-HD (final concentration 100 μmol/L) before H/R. In 5-HD + S group, preconditioning was performed with 5-HD 100 μmol/L and 6% sevoflurane before H/R. The neuronal viability, apoptosis rate and expression of Bcl-2 and Bax were determined after 24 h reoxygenation.Results The neuronal viability was significantly lower,while the apoptosis rate and expression of Bcl-2 and Bax were significantly higher in the other 6 groups than in group C(P＜0.01).The neuronal viability and expression of Bcl-2 were significantly higher,while the apoptosis rate and Bax expression were lower in S1-3 groups than in group H/R. There was no significant difference in the parameters mentioned above between 5-HD and 5-HD + S groups(P＞0.05).The neuronal viability and expression of Bcl-2 were significantly lower, while the apoptosis rate and Bax expression were higher in S2, S3 and 5-HD + S groups than in group S1, and in group S3 than in group S2(P＜0.0l) .Conclusion Sevoflurane preconditioning can inhibit H/R-induced apoptosis in rat hippocampal neurons and reduce the injury to neurons in a concentration-dependent manner, and the underlying mechanism may be related to activation of mito-KATP channels, up-regulation of Bcl-2 expression and down-regulation of Bax expression.     

银杏叶提取物对周围神经损伤后运动神经元的保护作用

目的　研究银杏叶提取物在大鼠坐骨神经损伤后对运动神经元的保护作用。方法　SD大鼠 3 6只 ,按手术先后随机平分为银杏叶提取物 (EGb 761)组和生理盐水 (SAL)组。大鼠均制成坐骨神经部分切除后结扎断端的模型 ,术后每天经腹腔分别注射EGb 761(10 0mg/kg-1·d-1)和同体积的生理盐水直到取材。术后 2、4、6周取材 ,大鼠处死后取L4～ 6节段脊髓 ,经酶组化染色后观察乙酰胆碱脂酶 (AChE)及酸性磷酸酶 (ACP)的活性变化 ;冰冻切片硫槿染色后对前角大型运动神经元计数 ;电镜观察脊髓前角运动神经元超微结构的变化。结果　与对照组相比 ,银杏叶提取物组的乙酰胆碱脂酶、酸性磷酸酶活性、损伤侧前角运动神经元数目及前角运动神经元超微结构 ,均有明显的改善。结论　银杏叶提取物对周围神经损伤后的脊髓前角运动神经元损害有保护作用     

丹参注射液椎管内局部灌注对急性脊髓损伤的保护作用

目的 探讨丹参对急性脊髓损伤的防治作用。方法 以改良Allen's法造成兔不完全性脊髓损伤的模型,硬膜下插管。随机分成丹参治疗组和对照组。术后按每天0.3ml/kg体重的总量分4次从硬膜下导管推入丹参注射液,对照组推入生理盐水。损伤后8、72h对脊髓损伤区进行过氧化物歧化酶(SOD)、丙二醛(MDA)、组织形态学观察、神经元凋亡、bcl-2等进行评价。结果 丹参组SOD含量高于对照组(P<0.01),MDA含量低于对照组(P<0.01)。细胞凋亡数目TUNEL法丹参组低于对照组(P<0.01),流式细胞术检测凋亡丹参组低于对照组(P<0.05)。bcl-2的表达丹参组高于对照组(P<0.05)。神经元及神经纤维变性、坏死轻于对照组。结论 丹参能改善损伤脊髓微循环,抑制和减轻脊髓损伤后的两种死亡方式坏死和凋亡。     

依达拉奉对过氧化氢刺激神经细胞的保护作用及机制研究

目的 探讨依达拉奉对神经元的保护作用及其保护机制.方法 提取胎龄16 ～ 18 d的孕大鼠皮层组织,消化、离心后培养,鉴定神经元细胞纯度90％以上.实验共分为3组:空白对照组、过氧化氢(H2O2)处理组(300 μmol/L刺激0.5、2、6及12 h),依达拉奉预处理组(刺激前预防性应用500 μmol/L保护30 min,分组同H2O2处理组).电镜观察线粒体形态的变化,流式细胞仪检测凋亡细胞的比率,免疫印迹及免疫沉淀检测凋亡关键蛋白的活性及蛋白间的关系.结果 相比依达拉奉预处理组,H2O2处理组相同时间点的线粒体明显呈水泡样肿胀变及空泡样变.H2O2处理组刺激后0.5、2、6及12h细胞凋亡比率分别为14.40％±1.23％、45.50％±2.81％、56.40％±3.53％、62.50％±4.23％;与空白对照组比较神经元凋亡明显增加(F=274.8,P＜0.01).依达拉奉预处理组相应时间点的细胞凋亡比率分别为0.90％±0.07％、1.10％±0.08％、3.50％±1.90％、12.60％±1.10％;与H2 02处理组比较明显降低(F=362.7,P＜0.01).刺激0.5h后,磷酸化c-Jun氨基端激酶(p-JNK)、细胞质中细胞色素C、线粒体膜上B细胞白血病-淋巴瘤-2相关X蛋白(BAX)表达水平开始明显升高,直至12 h时达到顶峰;与此同时,细胞质中B细胞白血病-淋巴瘤-2关联死亡蛋白(BAD)、磷酸化BAD、BAX和14-3-3水平表现为持续性降低,而这些改变在依达拉奉预处理组均被抑制.结论 作为一种自由基清除剂,依达拉奉可能通过抑制JNK的活性、抑制BAD与14-3-3分离及抑制BAX选择性地由细胞质向线粒体移位来保护神经细胞.     

神经生长液含药血清对神经元生长和雪旺细胞增殖的影响

目的 观察神经生长液含药血清对体外培养的背根神经节神经元生长和雪旺细胞增殖的影响,探讨其促损伤神经修复的机制.方法 制备神经生长含药血清;采用新生大鼠背根神经节及雪旺细胞体外培养,通过形态学分析,观察神经生长液含药血清对背根神经节神经元突起生长的影响;采用MTr、BrdU标记和细胞计数法,观察神经生长液含药血清对雪旺细胞活力及其增殖的影响.结果 高剂量的神经生长液含药血清,可有效地促进大鼠背根神经节神经元生长;高、低剂量的神经生长液含药血清均能显著增加大鼠雪旺细胞的活力,促进雪旺细胞增殖.结论 神经生长液含药血清具有促进神经元生长、增强雪旺细胞活力、促进雪旺细胞增殖作用.     

NSCs在OECs诱导下定向分化及神经元电生理特性研究

目的探索大鼠嗅鞘细胞（OECs）对神经干细胞（NSCs）分化的影响,并记录分化后神经元电生理特性。方法在无血清改良Eagle培养基（DMEM／F12）培养的NSCs中,加入OECs条件培养基,观察分化情况,巢蛋白（nestin）鉴定NSCs、神经丝蛋白200（NF200）鉴定神经元、膜片钳检测神经元电生理特性。结果OECs能促进NSCs分化为神经元,分化后的神经元记录到快速激活快速失活、能被河豚毒素（TTX）特异阻断的钠电流及慢激活慢失活、能被四乙基氯化铵（TEA）特异阻断的延迟整流性钾电流。结论OECs能诱导NSCs分化,分化后的神经元具有活跃的电生理特性,具有替代凋亡、坏死神经元的潜能。     

Magnetic resonance microscopy of mammalian neurons

Magnetic resonance imaging (MRI) is now a leading diagnostic technique. As technology has improved, so has the spatial resolution achievable. In 1986 MR microscopy (MRM) was demonstrated with resolutions in the tens of micrometers, and is now an established subset of MRI with broad utility in biological and non-biological applications. To date, only large cells from plants or aquatic animals have been imaged with MRM limiting its applicability. Using newly developed microsurface coils and an improved slice preparation technique for correlative histology, we report here for the first time direct visualization of single neurons in the mammalian central nervous system (CNS) using native MR signal at a resolution of 4–8 μm. Thus MRM has matured into a viable complementary cellular imaging technique in mammalian tissues.     

Neuronal-glial Interactions Define the Role of Nitric Oxide in Neural Functional Processes

Nitric oxide (NO) is a versatile cellular messenger performing a variety of physiologic and pathologic actions in most tissues. It is particularly important in the nervous system, where it is involved in multiple functions, as well as in neuropathology, when produced in excess. Several of these functions are based on interactions between NO produced by neurons and NO produced by glial cells, mainly astrocytes and microglia. The present paper briefly reviews some of these interactions, in particular those involved in metabolic regulation, control of cerebral blood flow, axonogenesis, synaptic function and neurogenesis. Aim of the paper is mainly to underline the physiologic aspects of these interactions rather than the pathologic ones.