氯化锰对大鼠中脑多巴胺能神经元毒性的研究

本文通过锰诱导多巴胺能神经元凋亡及其可能的神经化学机制的研究 ,进而探讨锰中毒与帕金森病发病的相互关系。分离培养大鼠中脑黑质多巴胺能神经元用不同剂量 Mn Cl2 处理后 ,用荧光染料进行染色 ,观察了凋亡神经元数量。用腹腔注射及脑内单侧注射 Mn Cl2 染毒方法处理大鼠 ,并采用脑内微透析技术和高效液相色谱 -电化学方法 (HPLC-ECD)在活体检测了术后不同时间的纹状体细胞外液中 DA及其代谢产物 DOPAC、HVA以及 5 -HT的代谢产物 5 -HIAA等的含量 ;同时作丙二醛含量和过氧化物歧化酶活性检测。结果发现 ,凋亡神经元的细胞核缩小、不规则、染色质呈块状深染 ,凋亡细胞数量随 Mn Cl2 剂量升高而增多。Mn Cl2 脑内注射侧与注射对侧相比 ,术后 4、7、10、2 0 d的 DA、DOPAC、HVA和 5 -HIAA含量均有不同程度的降低。腹腔染毒高、低剂量组 2 0 d后大鼠整体纹状体匀浆的上述指标也明显降低。此外 ,染毒大鼠纹状体中丙二醛水平随染毒剂量增高而增高 ,过氧化物歧化酶活性随染毒剂量增高却下降。以上结果表明 ,锰中毒可能是引起帕金森病发病的原因之一     

慢性间歇性低压低氧对老年大鼠纹状体多巴胺含量及行为的影响

目的:探讨慢性间歇性低压低氧(CIHH)对老年大鼠纹状体多巴胺(DA)及其代谢产物含量以及相关行为的影响。方法:用CIHH氧仓处理大鼠30 d,通过黏附物去除实验、倾斜面实验和水平绳实验检测大鼠行为的改变,通过液相色谱-串联质谱(L,C-MS/MS)分析DA及其代谢产物二羟苯乙酸(DOPAC)和高香草酸(HVA)的含量。结果:老年组大鼠黏附物去除实验、倾斜面实验和水平绳实验中各行为参数均较成年组大鼠显著下降,CIHH处理后上述行为参数均有改善,但没有达到成年组水平;老年组大鼠DA及其代谢产物DOPAC和HVA含量均较成年组大鼠显著下降,老年CIHH组DA及其代谢产物DOPAC和HVA均升高,但没有达到正常成年组水平。结论:CIHH改善老年大鼠纹状体DA含量及行为衰退。     

Genistein对Parkinson病模型小鼠黑质纹状体通路的保护作用

为了研究大豆异黄酮活性成分genistein对1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)制备的去卵巢(OVX)Parkinson病(PD)模型小鼠黑质纹状体通路的保护作用,我们将OVX PD小鼠随机分为对照组、MPTP组、genistein预处理组和雌激素预处理组,采用免疫组织化学染色结合逆转录-聚合酶链式反应法(RT-PCR)检测黑质致密带(SNpc)神经元酪氨酸羟化酶(TH)的表达情况,采用高效液相色谱法(HPLC-ECD)检测小鼠纹状体(Str)多巴胺(DA)及其代谢物二羟基苯乙酸(DOPAC)和高香草酸(HVA)的含量。结果显示:Genistein及雌激素用药组SN内TH阳性神经元数量及THmRNA的表达水平较MPTP组显著升高(P<0.01)。MPTP组Str内DA及其代谢产物DOPAC和HVA的含量较对照组明显降低(P<0.01)。genistein及雌激素用药组Str内DA、DOPAC及HVA含量较MPTP组显著升高(P<0.01)。上述结果提示genistein对MPTP制备的PD模型小鼠黑质DA能神经元有明显的保护作用。     

PCOS合并不孕症患者心理健康状况及其与单胺神经递质的关系

目的：了解PCOS和非PCOS不孕症患者的心理健康状况、血清中单胺类神经递质的浓度，并探讨心理健康状况与其血清中单胺类神经递质浓度之间的关系，为不孕症的综合性治疗提供资料。方法：从本院不孕症门诊收集PCOS及非PCOS不孕症初诊患者各30例作为实验组和对照组，所有入组对象均完成精神症状自评量表（SCL-90）的自我测评和血清NE及代谢物MHPG，DA及代谢物HVA、DOPAC，5-HT及代谢物5-HIAA浓度的测定。结果：对两组的SCL-90各因子分进行比较．结果发两组在抑郁、焦虑因子得分上有明显的差异（P≤0．05）。实验组与对照组比较，其血清中5-HT及其代谢产物5-HIAA浓度，DA代谢产物HVA均明显低（P≤0．05），其它指标两组之间无显著性差异。在总体样本中，SCL-90的恐怖因子分与MHPG血清浓度呈显著正相关（r=0.277，P=0.03），在实验组SCL-90的敌对因子分与血清DOPAC浓度呈显著负相关（r=-0．416，P〈0．02）。结论：PCOS患者较非PCOS妇女存在明显的心理障碍问题，主要表现在焦虑与抑郁情绪方面；PCOS不孕症患者的血清中5-HT及其代谢产物5-HIAA浓度，DA代谢产物HVA明显下降：心理问题可能是PCOS不孕症的重要因素之一。     

外源性EGF对中年大鼠运动活性及纹状体多巴胺含量的影响

目的:探讨表皮生长因子(EGF)对中年大鼠运动活性以及纹状体多巴胺含量的影响。方法:经皮给予健康18月龄大鼠不同剂量EGF(0.01,0.05,0.1,0.15,0.3 mg/ml),通过旷场实验检测大鼠运动行为的改变,通过液相色谱-串联质谱分析多巴胺的含量变化。结果:与对照组相比,小剂量EGF组大鼠(0.01,0.05 mg/ml)旷场实验中各行为参数没有变化;中等剂量EGF组大鼠(0.1,0.15 mg/ml)旷场实验中闻嗅行为、探索行为、趋触性行为、运动行为和理毛行为改善;大剂量EGF(0.3 mg/m1)组大鼠旷场实验中各行为参数下降。纹状体多巴胺及其代谢产物DOPAC和HVA的含量与对照组相比,小剂量EGF(0.01 mg/rnl)组开始上升,中等剂量EGF(0.1 mg/ml)组达到峰值,大剂量EGF(0.3 mg/ml)组下降。结论:EGF对中年大鼠运动活性以及纹状体多巴胺的含量均有影响。     

HPLC—ECD法分析中枢单胺类递质及其在免疫应答过程中的动态变化

建立快速、简便反相离子对高效液相色谱—电化学检测分析法,一次同时测定生物样品中单胺类递质(NE.E.DA、5—HT)及其前体氨基酸(Tyr、Trp)和主要代谢产物(HVA、5-HIAA共8种化合物。应用该法检测了SRBC免疫小鼠大脑皮质、间脑、脑干8种单胺类化合物的变化规律。免疫后第3天,皮质DA/HVA、间脑NE含量显著降低(P<0.05);第5天,间脑5-HT和脑干5-HIAA含量明显升高(P<0.05)。支持免疫应答可以影响中枢单胺类递质代谢的推论。     

银杏叶提取物对帕金森病模型小鼠多巴胺能神经元保护作用研究

目的研究银杏叶提取物（GBE）对帕金森病模型小鼠黑质（SN）多巴胺（DA）能神经元的保护作用。方法36只C5,Bk小鼠随机3组,每组12只。其中,帕金森病（PD）模型组的小鼠采用1-甲基-4-苯基-1,2,3,6-四氢吡啶（MPTP）腹腔注射（30mg／kg×5d）诱导PD;GBE预处理组的小鼠于注射MPTP前2h腹腔注射GBE（60mg／kg×8d）;正常对照组的小鼠只注射等体积生理氯化钠溶液。应用免疫组织化学染色观察小鼠黑质致密带（SNzc）酪氨酸羟化酶（TH）免疫反应阳性细胞数量的变化,用高效液相色谱法（HPLC-ECD）检测小鼠纹状体（Str）内DA及其代谢物二羟基苯乙酸（DOPAC）和高香草酸（HVA）含量。结果PD模型组小鼠SN内酪氨酸羟化酶（TH）阳性细胞数量、Str内DA及其代谢产物DOPAC和HVA的含量明显减少（P〈0．01）,GBE预处理组小鼠SN内TH阳性细胞数量、Str内DA及其代谢产物DOPAC和HVA的含量明显增多（P〈0.05）,但仍低于正常对照组（P〈0．01）。结论GBE对MPTP致帕金森病小鼠SNDA能神经元具有明显的保护作用。     

针刀和电针对膝骨关节炎大鼠痛阈和中枢单胺类神经递质的影响

目的:对比观察针刀松解法、电针对膝骨关节炎(KOA)大鼠痛阈和中枢神经递质的影响。方法:80只SD大鼠被随机分为空白对照组、模型组、针刀组和电针组,4%木瓜蛋白酶溶液与0.3 mol/L半胱氨酸溶液(1∶1混置0.5 h)的混合液20μL,分别于造模第1 d、4 d、7 d注射于大鼠左侧膝关节腔中,4周后,治疗组分别以针刀松解法或电针治疗,共3周。采用光辐射热法检测大鼠痛阈,膝关节HE染色,ELISA法分别测定大鼠中脑、下丘脑、延脑、海马、脊髓等不同部位5-HT、NE、DA含量。结果:膝骨关节炎大鼠造模后痛阈显著降低(P0.01),而针刀松解法或电针治疗后,第1周、第2周、第3周痛阈值均明显高于模型组(P0.05,P0.01);针刀和电针疗法可以改善大鼠膝骨关节炎病理组织损伤,可调节大鼠中脑、下丘脑、海马、脊髓等部位5-HT的合成与代谢,调节脊髓、下丘脑和延脑NA合成和代谢,调节中脑DA合成与代谢。结论:针刀和电针疗法对膝骨关节炎大鼠痛阈、组织形态学和中枢单胺类神经递质的含量有一定的调节作用。提示2种疗法可通过调节中枢神经5-羟色胺和儿茶酚胺类神经递质的合成和代谢的失衡状态,以减轻关节软骨损伤,缓解膝骨关节炎发生发展时出现的疼痛。     

过表达Nurr1基因的骨髓间充质干细胞的诱导及移植治疗帕金森病的研究

目的:探讨Nurr1基因修饰大鼠骨髓间充质干细胞(mesenchymalstemcells,rMSCs)脑内移植对帕金森病(parkinsondiseasePD)大鼠的治疗作用。方法:用脂质体转染法转染PcDNA3.1(+)-Nurr1入rMSCs并稳定表达.然后移植大鼠PD模型纹状体内;观察行为学变化并用免疫组化、RT-PCR等方法检测移植细胞的Nurr1、DAT和TH表达;利用高效液相色谱检测多巴胺(DA)、二羟苯乙酸(DOPAC)和高香草酸(HVA)含量。结果:Nurr1-rMSCs组和rMSCs组移植治疗8周内PD大鼠旋转行为均得到一定的改善(P<0.05);移植后2～4周Nurr1-rMSCs组较rMSCs组改善程度更为显著(P<0.05),但第8周时二组行为学差异无统计学意义(P>0.05)。免疫组化显示Nurr1-rMSCs能够稳定表达Nurr1且少量细胞表达DAT,但未发现TH阳性细胞。而rMSCs组和对照组则均未发现有Nurr1、DAT、TH表达;RT-PCR检测显示移植后2～8周,Nurr1-rMSCs组移植区有Nurr1和DATmRNA表达,但未发现THmRNA表达;两治疗组DA、DOPAC和HVA含量均较对照组增高(P<0.05)。结论:Nurr1基因转染大鼠骨髓间充质干细胞移植大鼠纹状体可以在一定时期内存活并有效表达,同时可提高纹状体DA含量,改善模型鼠症状,为治疗PD的研究提供了实验依据。     

不同电针刺激强度和频率对大鼠脑内单胺类神经介质有不同的影响

比较了两种不同电针刺激强度(负载电压峰-峰值3伏,6伏)和频率(10赫兹,200赫兹)对大鼠不同脑区内5-羟色胺(5-HT)及其代谢产物5-羟吲哚乙酸(5-HIAA)、去甲肾上腺素(NA)和多巴胺(DA)水平的影响。70只体重为250克左右的健康雄性大鼠随机分为五个实验组:Ⅰ对照组,Ⅱ低     

Neurotransmitter levels in two populations of larval Fundulus heteroclitus after methylmercury exposure

The effects of methylmercury (MeHg) exposure on neurotransmitter (NT) levels in larval mummichogs (Fundulus heteroclitus) obtained from a mercury-polluted site (Piles Creek (PC), NJ) and a reference site (Tuckerton (TK), NJ) were examined. Population differences between PC and TK larvae in neurochemical composition and in neurochemical changes in response to MeHg intoxication were found. Heads of untreated PC larvae (7 days posthatch (dph)) contained considerably higher levels of dopamine (DA) and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) than TK. However, they had comparable levels of serotonin (5-hydroxytryptamine (5-HT)) and 5-hyroxy-3-indoleacetic acid (5-HIAA)/5-HT ratios. Changes in NTs with age were noticed, especially in PC larvae. Exposure of larvae to 10 microg/l MeHg induced neurochemical alterations. A significant increase in DA and 5-HT, as well as depressed dopaminergic and serotonergic activity (i.e. decreased DOPAC/DA, HVA/DA and 5-HIAA/5-HT ratios) were seen in TK larvae. Exposure of PC larvae to 10 microg/l MeHg reduced 5-HT at 14 dph, increased serotonergic activity at 7 dph, and altered dopaminergic activity (i.e. increased DOPAC/DA ratios, but decreased HVA/DA ratios). Changes in DA levels were inconsistent over time. The DA level, which was considerably higher than the control at 7 dph, was significantly lower than the control at 14 dph. For the two populations, the level of 5-HT and serotonergic activity, as well as DOPAC and HVA levels, were correlated with previously noted spontaneous activity. The changes in NT levels after exposure to MeHg are an indication of neurological dysfunction in larvae.     

Monoamine levels after pilocarpine-induced status epilepticus in hippocampus and frontal cortex of Wistar rats

Pilocarpine-induced status epilepticus (SE) is an useful model to study the involvement of neurotransmitter systems as epileptogenesis modulators. Some researches have shown that pharmacological manipulations in dopaminergic, serotonergic, and noradrenergic systems alter the occurrence of pilocarpine-induced SE. The control group was treated with 0.9% saline (control group, s.c.). Another group of rats received pilocarpine (400 mg/kg, s.c.) and both groups were sacrificed 24 h after the treatment. This work was performed to determine the alterations in monoamine levels (dopamine (DA), serotonin (5-HT) and norepinephrine (NE)) and their metabolites (3,4-hydroxyphenylacetic acid (DOPAC), homovanilic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA)) after pilocarpine-induced SE in hippocampus and frontal cortex of adult rats. The monoamines and their metabolites were determined by reverse-phase high-performance liquid chromatography with electrochemical detection. DA and 5-HIAA concentrations were not altered in the hippocampus of the pilocarpine group, but in the same group the 5-HT (160%), DOPAC (316%) and HVA (21%) levels increased, whereas, the NE (47%) content declined. For the frontal cortex determinations, there was an increase of 20 and 72% in DA and DOPAC levels, respectively, and a decrease in NE (32%), 5-HT (33%) and 5-HIAA (19%) concentrations, but HVA content remained unaltered. These results indicate that pilocarpine-induced SE can alter monoamine levels in different ways depending on the brain area studied, suggesting that different mechanisms are involved.     

The neurotoxic actions of 1-methyl-4-phenylpyridine (MPP+) are not prevented by deprenyl treatment

1-Methyl-4-phenylpyridine (MPP+) injected into the cerebral ventricles (ICV) of mouse caused depletions of striatal dopamine (DA)(-42%), 3,4-dihydroxyphenylacetic acid (DOPAC) (-34%) and homovanillic acid (HVA) (-16%) content without significant reductions in levels of noradrenaline (NA), serotonin (5-HT) or 5-hydroxyindoleacetic acid (5-HIAA). When deprenyl was administered before MPP+, striatal DA and its metabolites were further depleted, and striatal NA and 5-HT levels also were reduced. Further, whilst ICV MPP+ alone failed to influence the biochemistry of the limbic areas (nucleus accumbens plus tuberculum olfactorium), in the presence of deprenyl MPP+ caused 20-40% reductions in levels of limbic NA, DA, DOPAC, HVA, 5-HT and 5-HIAA. Therefore, deprenyl treatment does not prevent the neurotoxic actions of MPP+; indeed, a more extensive neurotoxicity for MPP+ is revealed in the presence of this monoamine oxidase inhibitor.     

From a standpoint of psychiatry: effects of conditioned fear stress on monoaminergic systems in the rat brain]

The effects of electric footshock stress(EFS) and conditioned fear stress(CFS) on dopamine(DA) and serotonin(5-HT) metabolism in seven various brain regions of the rat were studied by measuring dihydroxyphenylacetic acid(DOPAC), homovanillic acid(HVA) and 5-hydroxyindoleacetic acid(5-HIAA). EFS for 30 min increased DOPAC and HVA levels in all seven brain regions and increased 5-HIAA levels in the medial prefrontal cortex(mPFC), nucleus accumbens and amygdala. CFS(exposure to an environment paired previously with footshock) increased plasma corticosterone levels and defecation, and induced freezing behavior. It also increased DOPAC levels in the mPFC, paraventricular nucleus of the hypothalamus and lateral hypothalamus, increased HVA levels in the mPFC and amygdala, and increased the 5-HIAA level in the mPFC. In contrast to EFS, which increased DA and 5-HT metabolism in several other brain regions, increased metabolism of both DA and 5-HT was especially marked in the mPFC after CFS. In this model, two classes of anxiolytics were examined for effects on freezing behavior. The benzodiazepine diazepam, a classical anxiolytic, reduced the freezing response. The new anxiolytic ipsapirone, a selective 5-HT1A agonist, also reduced the freezing response. These findings suggest the usefulness of this model for detecting the anxiolytic potential of drugs and examining the relation between 5-HT and anxiety.     

Behavioral and neurochemical alterations evoked by p-Chlorophenylalanine application in rats examined in the light-dark crossing test

The aim of the present study is to examine the effects of serotonin synthesis inhibition with p-Chlorophenylalanine (p-CPA) in rats on (1) anxiety behavior examined in the light-dark crossing test and, (2) regional brain concentration of monoamines (NA, DA and 5-HT) and their metabolites (MHPG, DOPAC, HVA and 5-HIAA) as well as GABA in the hypothalamus, amygdala, hippocampus, midbrain central gray matter and the frontal cortex. Treatment of animals with p-CPA produced a significant increase in time out from the illuminated part of the chamber and in time of locomotor activity in the illuminated part of the chamber. HPLC analysis showed a significant reduction of 5-HT and 5-HIAA concentration in all examined brain regions with the exception of the frontal cortex. Additionally, a significant decrease in DA and its metabolites, DOPAC and HVA occurred in the hypothalamus and amygdala. Moreover, we observed a significant decrease in frontal cortex NA concentration after p-CPA administration. The results of our study suggest that administration of p-CPA is effective in reduction of anxiety through depletion of 5-HT accompanied by diminution of catecholamines, especially DA and its metabolites in the main emotional brain regions.     

Effect of sex and age on brain monoamines and spatial learning in rats

The concentrations of noradrenaline (NA), dopamine (DA), serotonin (5-HT), and their metabolites were measured in the prefrontal cortex, caudate-putamen, and hippocampus in young (3 months) and aged (27–31 months) Wistar rats of both sexes. Age-related changes were found in prefrontal NA and HVA/DA ratio, striatal DA and DOPAC/DA ratio, and striatal and hippocampal 5-HT and 5-HIAA/5-HT ratio. Age and sex dependent changes were found in striatal DA and DOPAC/DA ratio, and hippocampal MHPG-SO₄/NA ratio. The aged rats were tested in spatial discrimination and reversal tasks in a T maze. The effects of α₂-agonist medetomidine (3 μg/kg) on the task performance were assessed in relation to individual variation in monoamine metabolism. Medetomidine impaired spatial discrimination learning of the aged rats by interacting with the hippocampal 5-HT turnover. Medetomidine improved reversal learning through an interaction with the striatal DA turnover and reduced the number of perseverative errors after reversal, mainly due to its interaction with the prefrontal NA turnover. It is concluded that the memory enhancing effect of drugs acting through the brain monoamine systems is highly dependent on the stage of degeneration of these systems that show considerable individual variation in aged animals.     

Age-related changes in dopaminergic and serotonergic indices in the rat forebrain

Age-related changes in the content of dopamine (DA), homovanillic acid (HVA), dihydroxyphenylacetic acid (DOPAC), 3-methoxytyramine (3-MT), serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in anterior cerebral cortex, hippocampus and striatum of the rat have been investigated using HPLC with electrochemical detection. A significant decrease in HVA was observed in the striatum and hippocampus of the aged (27 months) animals, as compared to the controls (2.4 to 2.6 months). A significant decrease in DA levels was also observed in the hippocampus but not in the striatum. In contrast, the level of DA in the cerebral cortex was markedly increased in the aged animals. A concomitant increase in 3-MT level was observed. Finally the level of 5-HIAA was significantly increased in striatum and hippocampus.     

Lipoic acid effects on lipid peroxidation level,superoxide dismutase activity and monoamines concentration in rat hippocampus

The purposes of the present work were to verify lipid peroxidation level, superoxide dismutase (SOD) activity and monoamines (dopamine (DA), norepinephrine (NE), serotonin (5-HT)), and their metabolites (3,4-hydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA)) contents in rat hippocampus after lipoic acid (LA) administration. Wistar rats were treated with 0.9% saline (i.p., control group) and LA (10, 20 or 30 mg/kg, i.p., LA10, LA20 and LA30 groups, respectively). After the treatments all groups were observed for 24 h. In LA20 group only there was a significant decrease in lipid peroxidation level. However, no alteration was observed in SOD activity in groups treated with LA. The NE and DA levels were increased only in 20 mg/kg dose of LA in rat hippocampus. Serotonin content and their metabolite 5-HIAA levels was decreased in same dose of LA. On the other hand, DOPAC and HVA levels did not show any significant change. The reduction in lipid peroxidation level and alterations in hippocampal monoamines can be suggested as a possible brain mechanism from this antioxidant. The outcome of the study may have therapeutic implications in the neurodegenerative diseases.