尼古丁对帕金森病大鼠纹状体GDNF和多巴胺含量的影响

目的 研究尼古丁对帕金森病（PD）大鼠纹状体脑胶质细胞源性神经营养因子(GDNF)和多巴胺（DA）含量的影响。方法 将6－羟多巴胺（6－OHDA）立体定向注射到大鼠右侧中脑腹侧背盖部（VTA）和黑质致密部（SNpc)，建立PD大鼠模型。采用生化、免疫组织化学方法观察不同剂量尼古丁对PD大鼠的作用，检测纹状体GDNF表达及DA含量的变化。结果 造模前及造模后皮下注射尼古丁的PD大鼠，纹状体GDNF表达及DA含量较PD组有明显改善（P＜0．05）。结论 尼古丁可减轻6－OHDA对黑质DA能神经元的损伤，对PD大鼠具有保护作用。     

离体帕金森病动物模型制作的研究

目的 :研究用 6 -羟多巴胺 (6 - OHDA)对中脑黑质多巴胺能神经元的选择性神经毒性作用建立离体帕金森病实验模型的方法。方法 :用 6 - OHDA(浓度分别为 0 .0 1m M、 0 .0 5 m M、 0 .1m M)孵育大鼠离体脑片 1小时 ,用抗酪氨酸羟化酶免疫组织化学方法观测黑质阳性细胞体及突起的变化。结果 :随着 6 - OHDA浓度的增加 ,离体脑片黑质 TH阳性细胞突起及纤维数逐渐减少。结论 :6 - OHDA孵育大鼠离体脑片可复制成帕金森病离体模型。     

左旋多巴治疗对实验性帕金森病大鼠黑质纹状体TNF—a表达的影响

目的　研究左旋多巴 (L - dopa)治疗对实验性帕金森病 (PD)大鼠黑质纹状体肿瘤坏死因子(TNF-α)表达的影响。方法　黑质定位注射 6 -羟多巴胺 (6 - OHDA )制备偏侧 PD大鼠模型 ,经 5 0～ 10 0 mg/ kg体重 L - dopa灌胃治疗 4周后 ,检测双侧额叶皮质、黑质和纹状体区域 TNF-α的表达。结果　 6 - OHDA损毁侧黑质和纹状体 TNF-α含量和阳性细胞面密度分别显著高于健侧 (均 P<0 .0 5 )。损毁侧与健侧 TNF-α含量的比率随 L - dopa治疗用量的增加而增高 ,且均显著高于对照组 (P<0 .0 5 )。结论　 L - dopa治疗进一步加剧了PD大鼠黑质纹状体区域 TNF-α的高表达。     

帕金森病大鼠黑质NurrlmRNA表达的动态变化

目的　探讨帕金森病大鼠黑质核内受体相关因子 1(Nurr1)mRNA表达的动态变化。方法　通过脑立体定位注射 6 羟基多巴胺 (6 OHDA)的方法建立大鼠帕金森病 (Parkinson’sdisease,PD)模型 ,采用HE染色 ,酪氨酸羟化酶 (TH)免疫组织化学染色、原位杂交技术 ,选择 6 OHDA注射术后 1d、3d、5d、7d、2 1d为研究时点 ,观察大鼠PD模型形成过程中黑质TH 多巴胺细胞数量及Nurr1mRNA表达的改变。结果　与健侧比较 ,注射 6 OHDA 5d组损毁侧黑质TH 细胞显著减少 (P <0 .0 1) ,2 1d时仅为健侧的 15 %且出现明显的旋转行为 ;同时 ,注射 6 OHDA 1d组损毁侧黑质Nurr1mRNA表达即开始下降 ,且以 3d组最为显著 (P <0 .0 1) ,7d以后各组完全消失。结论　本实验研究结果表明 ,6 OHDA能下调大鼠黑质Nurr1mRNA的表达早于诱导多巴胺细胞的死亡     

被动吸烟对大鼠纹状体多巴胺及黑质自由基含量的影响

目的研究被动吸烟对帕金森病(PD)大鼠的影响,探讨其作用机制。方法通过6-羟多巴胺(6-O-HDA)脑立体定向注射术建立大鼠PD模型。术前4周开始被动吸烟及术后持续2周为预防组;术后3周给予被动吸烟持续2周为治疗组。采用生化的方法观察PD大鼠纹状体黑质自由基、抗氧化剂及多巴胺含量的变化。结果吸烟治疗组和吸烟预防组大鼠黑质自由基及抗自由基酶较对照组有明显改善(P<0.05);吸烟预防组PD大鼠纹状体DA含量较对照组有明显改善(P<0.05);吸烟治疗组PD大鼠纹状体DA含量较对照组无变化(P>0.05)。结论被动吸烟能减轻黑质纹状体DA能神经元的损伤。     

铁在大鼠黑质多巴胺能神经元损伤中作用研究

目的：观察铁在多巴胺能神经元损伤过程中的作用，并探讨铁在帕金森病Parkinson disease，PD)起病阶段的作用。方法：通过PD大鼠模型，采用生化、TUNEL方法观察6-羟基多巴胺(6-OHDA)脑立体定向注射1、7、14、21d PD黑质铁浓度、自由基以及黑质细胞凋亡数变化。结果：1～21d PD大鼠黑质铁浓度、自由基及凋亡细胞数随时间增加而增加，并显著高于对照组。结论：铁在PD发病中具有重要作用。     

左旋多巴对帕金森病大鼠黑质多巴胺能神经元及纹状体多巴胺递质的影响

目的　研究长期应用左旋多巴对帕金森病 (PD)大鼠黑质多巴胺 (DA)能神经元和DA递质的影响。方法　采用 6 羟基多巴胺 (6 OHDA)制备部分损毁和严重损毁的PD大鼠模型 ,给两种模型口服不同剂量左旋多巴 /苄丝肼 3个月 ,通过观察大鼠旋转行为、酪氨酸羟化酶 (TH)免疫组化染色和高效液相色谱 电化学检测仪 (HPLC ECD)检测纹状体单胺类递质 ,研究左旋多巴对PD大鼠残存的黑质DA能神经元的影响。结果　 (1)左旋多巴对PD大鼠的旋转行为无明显影响 ;(2 )TH阳性细胞数损毁侧 /非损毁侧比值在左旋多巴喂药组和不喂药对照组的差异无显著意义 (P >0 0 5 ) ;(3)在严重损毁组 ,大剂量左旋多巴使PD大鼠损毁侧DA和 3,4二羟基苯乙酸 (DOPAC)水平明显升高(P <0 0 1)。结论　长期使用左旋多巴对 6 OHDA单侧损毁的PD大鼠残存的黑质DA能神经元无毒性作用。     

被动吸烟对帕金森病大鼠旋转行为和纹状体多巴胺含量的影响

目的：观察被动吸烟对帕金森病（PD）大鼠的影响,以验证流行病学研究的结论,为PD研制提供一新的线索。方法：用6－羟基多巴胺（6－OHDA）立体定向注入大鼠一侧黑质致密部和中脑被盖腹侧区建立侧侧PD模型,观察术前4周开始始予的被动吸烟（持续6周）和术后2周对成功模型给予的被动吸烟（持续2周）对阿朴吗啡诱发的旋转行为及纹状体DA含量的影响。结果：术前4周开始被动吸烟的大鼠旋转行为有减少趋势,受损侧纹状体DA含量较对照组升高,术后2周,成功模型给予的被动吸烟对PD大鼠的旋转行为及纹状体DA含量均无影响。结论;被动吸烟可减轻6－OHDA对黑质DNA能神经元的损伤。     

氧自由基在帕金森病发病中作用的实验研究

目的 观察氧自由基在帕金森病发病中的作用。方法 大鼠分为3组：帕金森病组、假手术组、对照组。帕金森病大鼠模型采用6羟基多巴胺(6—OHDA)制作。采用生化、电镜方法观察铁离子、氧自由基浓度及黑质超微结构变化。结果 帕金森病组大鼠铁离子、氧自由基浓度及黑质损伤程度均高于对照组和假手术组。结论 氧自由基在帕金森病发病中起着重要作用。     

被动吸烟对大鼠纹状体GDNF和多巴胺含量的影响

目的 :研究被动吸烟对帕金森病 (PD)大鼠的影响 ,探讨其作用机制。方法 :通过 6—羟多巴胺 (6 OH DA)脑立体定向注射术建立大鼠帕金森病模型。采用生化、免疫组织化学的方法观察PD大鼠纹状体脑胶质细胞源性神经营养因子表达 (GDNF)及多巴胺 (DA)含量的变化以及术前 4周开始给予被动吸烟 (持续 6周 )和术后 3周给予的被动吸烟持续 2周对上述指标的影响。结果 :术前及术后吸烟的PD大鼠纹状体DA含量、脑胶质源性神经营养因子表达较PD组有明显改善 (P <0 0 5 )。结论 :被动吸烟能减轻黑质纹状体DA能神经元的损伤     

尼古丁抑制6-羟基多巴胺损伤诱导的T淋巴细胞浸润

目的 采用6.羟基多巴胺(6-OHDA)部分损伤大鼠帕金森病模型,探讨尼古丁保护多巴胺能神经元的机制.方法 雌性SD大鼠60只采用随机数字表法分为三组:尼古丁高剂量治疗组(尼古丁2.0mg/kg腹膜腔内注射)、低剂量治疗组(尼古丁0.2mg/kg腹膜腔内注射)及模型对照组(生理盐水腹膜腔内注射).每组20只.注射7d后,分别接受单侧纹状体内6-OHDA 20ug注射,制作帕金森病模型.免疫组织化学及体视学方法定量分析黑质多巴胺能神经元和纹状体CD3、CD4和CD8阳性淋巴细胞数量.结果 6-OHDA注射4周后,模型对照组注射侧黑质酪氨酸羟化酶(TH)免疫阳性细胞为对照侧的25.27%;而在尼古丁低剂量和高剂量组,注射侧的TH免疫阳性细胞分别为相应对照侧的64.97%和67.24%.各组各时间点6-OHDA注射侧纹状体有明显的T淋巴细胞浸润.尼古丁治疗组浸润的T淋巴细胞数较模型对照组明显减少.差异有统计学意义(P<0.05),而CD4和CD8阳性细胞占总T淋巴细胞的比例在各组和各时间点基本一致,尼古丁治疗组和模型对照组比较差异无统计学意义(P>0.05).结论 尼古丁可抑制6-OHDA损伤诱导的T淋巴细胞浸润,对抗6-OHDA神经细胞毒性,保护多巴胺能神经元.     

The 6‐hydroxydopamine‐induced nigrostriatal neurodegeneration produces microglia‐like NG2 glial cells in the rat substantia nigra

Neuron/glial 2 (NG2)‐expressing cells are often referred to as oligodendrocyte precursor cells. NG2‐expressing cells have also been identified as multipotent progenitor cells. However, microglia‐like NG2 glial cells have not been fully examined in neurodegenerative disorders such as Parkinson's disease (PD). In the present study, we chose two rat models of PD, i.e., intranigral or intrastriatal injection of 6‐hydroxydopamine (6‐OHDA), since the cell bodies of dopamine (DA) neurons, which form a nigrostriatal pathway, are in the substantia nigra pars compacta (SNpc) while their nerve terminals are in the striatum. In the nigral 6‐OHDA‐injected model, activated NG2‐positive cells were detected in the SNpc but not in the striatum. In contrast, in the striatal 6‐OHDA‐injected model, these cells were detected in both the SNpc and the striatum. In both models, activated NG2‐positive cells were located close to surviving tyrosine hydroxylase (TH)‐positive neurons in the SNpc. In addition, activated NG2‐positive cells in the SNpc coexpressed ionized calcium‐binding adaptor molecule 1 (Iba1), a microglia/macrophage marker. Interestingly, these double‐positive glial cells coexpressed glial cell line‐derived neurotrophic factor (GDNF). These results suggest that microglia‐like NG2 glial cells may help protect DA neurons and may lead to new therapeutic targets in PD. © 2010 Wiley‐Liss, Inc.     

尼古丁抑制6-羟基多巴胺损伤诱导的CD8+T淋巴细胞浸润

目的:采用6-羟基多巴胺部分损伤大鼠帕金森病模型,探讨尼古丁保护多巴胺能神经元的机制。方法:动物分别接受尼古丁(0.2mg/kg或2.0mg/kg)或生理盐水腹膜腔内注射。注射7天后,尼古丁高、低剂量治疗组和模型对照组动物分别接受纹状体内6-OHDA20μg注射,制作部分损伤帕金森病模型。免疫组织化学及体视学方法定量分析黑质多巴胺能神经元和纹状体CD8+T淋巴细胞数量。结果:尼古丁低剂量治疗组和高剂量治疗组,6-OHDA注射侧的酪氨酸羟化酶免疫阳性细胞分别为相应对照侧的64.97±10.33%和67.24±12.67%;和模型对照组(25.27±11.79%)比较,差异有统计学意义(P<0.01)。此外,尼古丁也可明显减少纹状体CD8+T淋巴细胞浸润(P<0.05)。结论:尼古丁可能通过抑制CD8+T淋巴细胞浸润,保护多巴胺能神经元。     

Chronic Nicotine Treatment Increases nAChRs and Microglial Expression in Monkey Substantia Nigra After Nigrostriatal Damage

Our previous work had shown that long-term nicotine administration improved dopaminergic markers and nicotinic receptors (nAChRs) in the striatum of monkeys with nigrostriatal damage. The present experiments were done to determine whether nicotine treatment also led to changes in the substantia nigra, the region containing dopaminergic cell bodies. Monkeys were chronically treated with nicotine in the drinking water for 6 months after which they were injected with low dose of 1-methyl-4-phenyl-1,2,3,6-tetrahydrophridine (MPTP) for a further 6-month period. Nicotine was administered until the monkeys were euthanized 2 months after the last MPTP injection. Nicotine treatment did not affect the dopamine transporter or the number of tyrosine hydroxylase positive cells in the substantia nigra of lesioned monkeys. However, nicotine administration did lead to a greater increase in α3/α6β2* and α4β2* nAChRs in lesioned monkeys compared to controls. Nicotine also significantly elevated microglia and reduced the number of extracellular neuromelanin deposits in the substantia nigra of MPTP-lesioned monkeys. These findings indicate that long-term nicotine treatment modulates expression of several molecular measures in monkey substantia nigra that may result in an improvement in nigral integrity and/or function. These observations may have therapeutic implications for Parkinson’s disease.     

Neuroprotective effects of subthalamic nucleus high-frequency stimulation on substantia nigra neurons in a Parkinson''s disease rat model

BACKGROUND: Deep-brain stimulation has proven to be beneficial in the treatment of Parkinson's disease (PD) patients. OBJECTIVE: To investigate the effects of high-frequency stimulation (HFS) to the subthalamic nucleus (STN) on neuronal apoptosis and apoptosis-related gene expression in the substantia nigra pars compacta, and to analyze the neuroprotective effect of HFS-STN. DESIGN, TIME AND SETTING: Neuronal morphology experiments were performed in the Beijing Nearosurgical Institute from May to December in 2005. MATERIALS: Forty healthy, adult, Sprague Dawley rats were used to establish a PD model with a unilateral microinjection of 6-hydroxydopamine into two target areas of the right medial forebrain bundle. 6-hydroxydopamine was purchased from Sigma (USA); high-frequency electrical stimulator was produced by World Precision Instruments (USA); Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) kit was a product of Nanjing Jiancheng Technology Co., Ltd. (China); and Bcl-2 and Bax protein assay kit were purchased from Wuhan Boster Bioengineering Co., Ltd. (China). METHODS: Forty rats were randomly divided into three groups. The stimulation group (n = 15) received HFS-STN on the day of PD modeling. The PD model group (n = 15) was used to establish the PD model. The control group (n = 1 0) was injected with normal saline containing 0.2 g/L ascorbic acid into two areas of the right medial forebrain bundle. MAIN OUTCOME MEASURES: Survival of dopaminergic neurons in the substantia nigra pars compacta was determined using Nissl staining. Apoptosis of dopaminergic neurons was detected using TUNEL techniques. Expression of anti-apoptotic protein, Bcl-2, and pro-apoptotic protein, Bax, were assayed by immunohistochemistry. RESULTS: Following 6-hydroxydopamine injection, the number of substantia nigra pars compacta neurons was reduced in the stimulation and PD model groups, compared to the control group. At 2 and 4 weeks post-surgery, the grey value of Nissl stained images was significantly less in the PD model and stimulation groups (P < 0.05), and the stimulation group exhibited greater grey values compared to the model group (P < 0.05). At 2 and 4 weeks post-surgery, the number of apoptotic neurons was significantly less in the stimulation group compared to the model group (P < 0.05). In addition, Bcl-2 and Bax expression, as well as the Bcl-2/Bax ratio, was much higher in the stimulation group compared to the model group (P < 0.05). CONCLUSION: HFS-STN has a neuroprotective effect on dopaminergic neurons in the substantia nigra pars eompacta of PD rats by promoting Bcl-2 expression, inhibiting Bax expression, and reducing the number of apoptotic dopaminergic neurons.