蛋白酶体抑制剂诱导多巴胺能神经元变性伴包涵体形成

目的 观察蛋白酶体抑制剂诱导黑质多巴胺(DA)能神经元变性伴胞浆内包涵体形成，探讨蛋白酶体功能在帕金森病发病机制中的作用。方法将蛋白酶体抑制剂Lactacystin立体定向注射至大鼠黑质部位。免疫荧光观察黑质区DA神经元变性缺失及胶质细胞变化。免疫荧光双标法观察DA能神经元内蛋白聚集的包涵体及其主要成分α-共核蛋白(α-synuclein)、Parkin和泛素(ubiquitin)的表达。同时观察。DA能神经元发生细胞凋亡。结果注射Lactacystin第7天大鼠开始出现自发性活动减少，阿扑吗啡可诱导出旋转行为；3周后黑质部位酪氨酸羟化酶(TH)阳性细胞减少，呈剂量依赖性；小胶质细胞增生明显。TH与硫磺素、硫磺素与α-synuclein、硫磺素与Parkin、以及硫磺素与ubiquitin复合染色呈阳性；TH与TUNEL双染亦呈阳性。结论Lactacystin对多巴胺能神经元具有毒性作用，且导致蛋白聚集，包涵体形成。蛋白酶体功能异常可能在帕金森发病机制中起重要作用。     

蛋白酶体抑制剂诱导帕金森病大鼠模型行为学退行性改变的研究

目的观察蛋白酶体抑制剂诱导的帕金森病(PD)行为学退行性变化,探索其发病机制。方法将32只大鼠随机分成实验组和对照组,每组16只,将蛋白酶体抑制剂Lactacystin立体定向注射到实验组大鼠左侧黑质致密部,对照组注射等体积生理盐水。术后1、3、5、7、9、11、14、18和21d,追踪观察大鼠自主行为和阿扑吗啡诱导的旋转行为变化;开野实验观察大鼠自发运动行为改变。结果实验组给药后,随着时间推移大鼠开始出现渐进性自发性活动减少、动作缓慢、对外界刺激不自主竖毛、震颤;阿扑吗啡诱导的向健侧旋转运动逐渐增多。开野实验结果显示:实验组大鼠自发运动行为出现渐进性异常改变。结论蛋白酶体抑制剂Lactacystin单侧黑质致密部微量注射诱导的大鼠行为学呈渐进性发展,符合PD发病过程,说明蛋白酶体功能下降可能在PD发病机制起重要作用。     

蛋白酶体功能与帕金森病相关性实验研究

目的 观察蛋白酶体抑制剂诱导大鼠黑质多巴胺能神经元α-突触核蛋白（α-synuclein，α-Syn）的表达及聚集．探讨蛋白酶体功能在帕金森病（PD）发病中的作用机制。方法采用立体定向将蛋白酶体抑制剂Lactacystin注射至大鼠黑质部位。以免疫荧光法观察黑质区多巴胺能神经元变性缺失，并应用免疫荧光双标法观察多巴胺能神经元内蛋白聚集的包涵体及其主要成分α-Syn的表达．然后通过原位杂交分析α-Syn mRNA表达及Western印迹法检测黑质α-Syn表达量改变。结果注射Lactacystin第7天大鼠开始出现自发性活动减少．阿扑吗啡尚可诱导出旋转行为；3周后患侧黑质部位酪氨酸羟化酶（TH）阳性细胞明显减少。TH与硫磺素、硫磺素与α-Syn复合染色呈阳性。α-Syn mRNA表达量升高，蛋白表达水平增加。结论Lactacystin诱导大鼠黑质细胞α-Syn表达升高并出现蛋白聚集可能是导致PD发病的机制之一。     

应用蛋白酶体抑制剂Lactacystin建立有Lewy体的帕金森病大鼠模型

目的建立符合帕金森病(PD)病理特征———黑质细胞有Lewy体的PD大鼠模型。方法分别在大鼠一侧黑质致密部注射蛋白酶体抑制剂Lactacystin8mg(Lactacystin组)、等体积生理盐水(NS组)和6-羟基多巴胺(6-OHDA组)12mg;观察大鼠自主行为和阿朴吗啡诱导的旋转行为;光镜下观察中脑组织学改变;应用免疫组化染色观察黑质细胞α-synuclein表达和酪氨酸羟化酶(TH)阳性细胞数;测定纹状体区多巴胺和高香草酸含量。结果NS组大鼠未见行为异常;Lactacystin组大鼠出现进行性的运动迟缓、少动、震颤、头向健侧倾斜,注射阿朴吗啡后出现向健侧旋转运动;给药后3周黑质部TH阳性细胞数较NS组减少了83.29%(P<0.01),部分黑质细胞内出现α-synuclein免疫反应呈强阳性的Lewy体;纹状体多巴胺和高香草酸含量(154.82±37.17,98.66±18.81)较NS组明显减少(822.87±131.25,617.77±95.74)(均P<0.01);6-OHDA组大鼠出现与Lactacystin组类似的行为变化,黑质细胞亦显著减少,但未见Lewy体。结论利用蛋白酶体抑制剂Lactacystin阻碍α-synuclein的降解可以建立有Lewy体的PD大鼠模型。     

蛋白酶体抑制剂诱导多巴胺能神经元变性及诱导型一氧化氮合酶变化

目的探讨蛋白酶体（proteasome）功能下降在帕金森病（PD）发病机制中的作用，以及模型大鼠脑内黑质部位诱导型一氧化氮合酶（iNOS）是否参与蛋白酶体抑制剂Lactacystin诱导的多巴胺能神经元变性。方法将30只健康雄性SD大鼠分为5组（生理盐水对照组，1d组、3d组、1周组、3周组），每组6只。将蛋白酶体抑制剂Lactacystin立体定向注射至大鼠黑质部位，记录大鼠在不同时间点的行为学改变，并用免疫组化方法观察生理盐水对照组及不同时间点组（1d、3d，1周、3周）大鼠黑质区多巴胺能神经元变性及iNOS变化。结果Lactacystin注射1周后大鼠开始出现自发性活动减少，阿朴吗啡可诱导出旋转行为；3周后，30min旋转次数为258．90±11．56；实验3周组黑质部位TH阳性细胞减少。1d后iNOS阳性细胞明显增多，3d时达高峰，1周后开始下降，3周时基本消失。结论蛋白酶体功能下降可能是多巴胺能神经元变性的始动因素，而iNOS上调可能是多巴胺能神经元变性的重要过程。     

脂多糖注入黑质对大鼠黑质纹状体单胺类递质和行为的影响

目的　探讨脂多糖 (L ipopolysaccharide,L PS)对大鼠行为学和黑质纹状体单胺类递质的影响。方法　采用立体定位注射 5μg L PS入大鼠脑黑质 ,在不同时间点观察大鼠注射阿朴吗啡后的旋转行为学 ,及采用HPL C测定黑质纹状体单胺类递质的含量变化。结果　 L PS注射后 14、2 1、3 0 d,大鼠出现向注射侧的旋转行为 ,在黑质和纹状体 ,DA及其代谢产物随时间改变呈不同程度下降 (P<0 .0 5) ,而 5-HT仅有短暂下降 ,NA无变化。结论　 L PS注入黑质特异性损害 DA能神经元 ,可降低黑质纹状体 DA及其代谢产物含量 ,诱导大鼠产生旋转行为     

蛋白酶体抑制剂诱导动物帕金森病模型的研究进展

帕金森病是一种好发于中老年人的神经变性疾病,其发病机制不明.目前,应用蛋白酶体抑制剂诱导的帕金森病动物模型,其行为学、影像学、病理学和生化特征都与帕金森病的表现极为相似,它的出现将会为帕金森病发病机制及治疗方法的探讨提供新途径.     

蛋白酶体抑制剂诱导大鼠黑质变性伴包涵体形成

目的 观察蛋白酶体抑制剂Lactacystin诱导大鼠黑质变性伴包涵体形成及运动行为学的改变,探讨蛋白酶体功能下降在帕金森病(PDl发病机制中的作用. 方法 24只SD大鼠采用随机数字表法分为kactacystin实验组和生理盐水组.每组12只,Lactacystin实验组将蛋白酶体抑制剂Lactacystin立体定向注射人大鼠左侧黑质致密部(SNc).生理盐水组注射等体积生理盐水;观察大鼠自主行为和阿朴吗啡(APO)诱导的旋转行为的改变;Nissl染色法观察SNc病理改变;免疫组化法观察SNc及纹状体酪氨酸羟化酶(TH)和SNc中α-共核蛋白的表达;透射电镜观察SNc超微结构的改变. 结果 Lactacystin实验组大鼠给药7 d后出现自发性活动减少、动作缓慢、震颤、且症状逐步加重.APO可诱导出向健侧的旋转运动;Nissl染色发现Lactacystin实验组左侧SNc神经元数量减少,尼氏体结构松散;免疫组化结果表明21 d后Lactacystin实验组左侧SNc出现变性,TH免疫阳性神经元数量减少,α-共核蛋白表达增强,纹状体内TH免疫阳性纤维数量减少;电镜观察到蛋白质聚集形成的包涵体. 结论 Lactacystin单侧SNc注射可以诱导大鼠黑质变性伴包涵体形成及大鼠行为改变.蛋白酶体功能下降可能在PD发病机制中起重要作用.     

蛋白酶体抑制剂诱导帕金森病大鼠模型海马区HSP70表达

目的观察蛋白酶体抑制剂Lactacystin诱导帕金森病大鼠模型海马区HSP70表达。方法将Lactacystin 10μg（2μl）经立体定向仪注射到大鼠（Lactacystin组,n=36）左侧黑质致密部,对照组（n=36）以等体积生理盐水代替;分别在药物注射后24h、3d、5d、7d、9d、11d、14d、18d和21d提取海马标本,通过免疫组化和RT-PCR观察HSP70的表达。结果Lactacystin组大鼠海马区HSP70表达较对照组高,表现为注药24h后表达开始增高,5d达高峰,11d开始减少;且海马区表达分布呈CA3〉CA2〉CA1。结论Lactacystin诱导帕金森病大鼠海马区HSP70表达增高,且呈明显区域性和时间依从性;增加的热休克蛋白可能参与拮抗蛋白酶体抑制毒性而起到神经细胞保护作用。     

Circulating corticosterone alters the rate of neuropathological and behavioral changes induced by trimethyltin in rats.

When trimethyltin (TMT) is administered to rats, the plasma corticosterone concentration rises transiently 3 to 4 days later. We examined whether plasma corticosterone plays a causative role in the TMT-induced impairment of the hippocampus as assessed by pathological and behavioral tests. TMT-administered rats were supplementally treated with either adrenalectomy or metyrapone (twice daily for the first 7 days after TMT) in order to permanently deplete or transiently suppress circulating corticosterone. Loss of pyramidal cells in the CA1 and CA3 fields, mossy fiber sprouting, and impairment of spatial memory were observed after TMT intoxication. Adrenalectomy apparently aggravated both the hippocampal damage and the spatial memory impairment induced by TMT treatment. The TMT+metyrapone treatment groups exhibited a significant reduction in pyramidal cells in both the CA1 and the CA3 regions. However, the neuronal damage in CA1 was significantly different between the TMT and the TMT+metyrapone groups. Metyrapone significantly reduced the TMT-induced damage to pyramidal cells in CA1, but not CA3, and it also abolished mossy fiber sprouting. TMT-induced learning impairment and hyperactivity were alleviated by metyrapone treatment. It is thus concluded that both the high levels of corticosterone induced by TMT and the pathologically low levels of corticosterone induced by adrenalectomy will worsen the consequences of TMT.     

脂多糖与阿司匹林对应激所致大鼠行为性抑郁的对照研究

目的观察阿司匹林及细菌脂多糖对大鼠应激所致的行为性抑郁影响。方法将72只SD雄性大鼠随机分为对照组和应激组。应激组大鼠在16d内接受小同类型的应激，制备应激性抑郁症模型。采用开场试验检测大鼠的行为性抑郁，用甲基噻唑基四唑比色法测定淋巴细胞转化。结果慢性应激大鼠从第7～14天出现总活动路程、总活动时间和中区活动时间减少，呈现明显的行为性抑郁。腹腔注射细菌脂多糖(100μg／kg)可加重应激引起的行为性抑郁，并加强应激大鼠血清对正常淋巴细胞转化的抑制作用，导致正常大鼠的总活动路程显著缩短。阿司匹林(50mg／kg)对正常大鼠无显著性影响，但可减轻大鼠的行为性抑郁和应激大鼠血清对正常淋巴细胞转化的抑制作用。结论腹腔注射细菌脂多糖加重应激大鼠的行为性抑郁，阿司匹林可减轻大鼠的行为性抑郁。     

Effects of pregabalin on behavioral alterations induced by ketamine in rats

Objective:The aim of this study is to investigate the effects of pregabalin on the behavior of rats under the influence of ketamine, an NMDA receptor antagonist that mimics the symptoms of schizophrenia.Methods:Rats were injected with saline or 25 mg/kg ketamine intraperitoneally. After that, behavior modifications were investigated by the evaluation of stereotypy and hyperlocomotion, after treating rats with pregabalin (at doses of 30 mg/kg or 100 mg/kg) or placebo (saline solution).Results:The administration of pregabalin reduced ketamine-induced hyperlocomotion. However, neither doses of pregabalin had a significant effect on ketamine-induced stereotypy.Conclusion:This is the first study to investigate the effects of pregabalin using an animal model of psychosis. Furthermore, our results indicate that behavioral changes induced by ketamine in rats can be reversed with the use of pregabalin, suggesting its potential to treat psychotic symptoms.     

Functional, behavioral, and histological changes induced by transient global cerebral ischemia in rats: effects of cinnarizine and flunarizine

Temporary cerebral ischemia (15 min) produced by "four-vessel occlusion" in the rat causes neurological disorders, changes in behavior (locomotor hyperactivity), and neuronal damage in the neocortex, striatum, and especially the CA1 zone of the hippocampus. We have studied the effects of two calcium overload blockers, flunarizine (50 mg/kg p.o. twice a day) and cinnarizine (100 mg/kg p.o. twice a day), on these alterations. Cinnarizine markedly improved the functional abnormalities of ischemia but had little or no effect upon the neuronal damage. In contrast, flunarizine provided far greater neuronal protection but with less obvious effects upon behavioral parameters. However, there was evidence of sedation 2 h after treating animals with this dose of flunarizine that might have masked any positive effect of the drug on behavior. We conclude that under the present experimental conditions, there is no correlation between the early and late behavioral changes observed following a temporary cerebral ischemic episode and the histological damage observed in certain vulnerable neurons, particularly in the hippocampus, 72 h after the insult.