舒肌汤对L-DOPA诱发的帕金森病肌僵直大鼠的作用及其脑组织TH、DA含量和FosB、p-ERK蛋白的影响

目的:观察舒肌汤对左旋多巴(Levodopa,L-DOPA)诱发的帕金森病(Parkinson’s disease,PD)肌僵直模型大鼠的影响,并探讨其作用机制。方法:L-DOPA诱导建立PD肌僵直大鼠模型,随机分为模型组(等体积生理盐水),舒肌汤低、中、高剂量组(10、20、40 g/kg),同时设假手术组(等体积生理盐水)作为对照,每组6只大鼠,每天灌胃给药1次,连续给药28 d。给药完成后通过旋转次数实验、翻正反射实验、肌电图检测行为学表现。免疫组化检测脑组织酪氨酸羟化酶(tyrosine hydroxylase,TH)表达水平。ELISA检测脑纹状体组织多巴胺(dopamine,DA)和TH的含量。Western blot检测脑纹状体组织FBJ鼠科骨肉瘤病毒癌基因同源物B(FBJ Murine Osteosarcoma Viral Oncogene Homolog B,FosB)、磷酸化细胞外信号调节激酶(phosphorylation-extracellular signal-regulated kinase,p-ERK)蛋白表达水平。结果:与假手术组相比,模型组大鼠旋转次数、翻正反射时间与评分、肌肉动作电位波幅和潜伏期显著升高或延长(P<0.01),MCV显著降低(P<0.01);与模型组相比,舒肌汤组大鼠旋转次数、翻正反射时间与评分、肌肉动作电位波幅和潜伏期显著降低或缩短(P<0.05),MCV显著升高(P<0.01)。免疫组化结果显示舒肌汤可上调脑组织TH表达水平;ELISA结果显示舒肌汤可上调DA和TH含量。Western blot结果显示舒肌汤可下调FosB、p-ERK蛋白表达水平。结论:舒肌汤对帕金森病模型大鼠肌僵直有显著疗效,其作用机制可能与上调DA和TH含量、下调FosB、p-ERK蛋白表达有关。

血清GABA、BDNF、5-HT、DA及NE在胃食管反流病中的表达及临床意义

目的探讨血清γ-氨基丁酸(GABA)、脑源性营养因子(BDNF)、5-羟色胺(5-HT)、去甲肾上腺素(NE)及多巴胺(DA)在胃食管反流病(GERD)中的表达及临床意义。方法选取100例GERD患者作为GERD组、40例同期健康体检者为对照组,GERD组患者给予药物治疗8周,根据治疗效果分为效果良好组和效果不良组;对照组于体检时、GERD组于治疗前、治疗后(8周时)取外周静脉血,检测血清GABA、BDNF、5-HT、DA、NE、胃动素(MTL)、胃泌素(GAS)、胆囊收缩素(CCK)水平;采用匹兹堡睡眠质量指数(PSQI)、汉密尔顿抑郁量表(HAMD)、焦虑自评量表(SAS)、日常生活能力量表(ADL)评分评估GERD组治疗前后、对照组体检时的睡眠质量、抑郁程度、焦虑状态、日常生活能力;比较GERD患者治疗前后、效果良好及效果不良组食管括约压力、立位返流时间比、卧位反流时间比、总反流时间;采用Pearson分析GERD患者治疗前GABA、BDNF、5-HT、NE及DA水平与患者食管括约肌压力、立位返流时间比、卧位返流时间比、总返流时间比、MTL、GAS、CCK的相关性。结果GERD组治疗后血清GABA、BDNF、5-HT、NE、DA、MTL、GAS水平高于治疗前、但低于对照组,血清CCK水平及各量表评分均低于治疗前、但高于对照组(P<0.05);GERD组患者治疗后食管括约压力高于治疗前,立位返流时间比、卧位反流时间比、总反流时间均低于治疗前(P<0.05);30例疗效不良组GERD患者血清GABA、BDNF、5-HT、NE、DA、MTL、GAS水平及食管括约肌压力均低于70例疗效良好组,血清CCK水平、各量表评分、立位返流时间比、卧位反流时间比、总反流时间比均高于疗效良好组(P<0.05);GERD患者治疗前血清BDNF、5-HT、DA水平与MTL、GAS、食管括约肌压力呈正相关,与立位返流时间比、卧位反流时间比、总反流时间比、CCK呈负相关,GABA、NE与MTL、GAS、食管括约肌压力呈正相关,NE与立位返流时间比、CCK呈负相关性,GABA与立位返流时间比、总反流时间比、CCK呈负相关,差异有统计学意义(P<0.05)。结论GABA、BDNF、5-HT、NE及DA水平与胃内激素MTL、GAS、CCK的合成分泌及胃动力相关指标关系密切,这些神经递质可能参与GERD的发生和发展过程。

Ginsenoside Rb1 protects dopaminergic neurons from inflammatory injury induced by intranigral lipopolysaccharide injection

Accumulating studies suggest that neuroinflammation characterized by microglial overactivation plays a pivotal role in the pathogenesis of Parkinson’s disease.As such,inhibition of microglial overactivation might be a promising treatment strategy to delay the onset or slow the progression of Parkinson’s disease.Ginsenoside Rbl,the most active ingredient of ginseng,reportedly exerts neuroprotective effects by suppressing inflammation in vitro.The present study aimed to evaluate the neuroprotective and anti-inflammatory effects of ginsenoside Rbl in a lipopolysaccharide-induced rat Parkinson’s disease model.Rats were divided into four groups.In the control group,sham-operated rats were intraperitoneally administered normal saline for 14 consecutive days.In the ginsenoside Rbl group,ginsenoside Rb1(20 mg/kg)was intraperitoneally injected for 14 consecutive days after sham surgery.In the lipopolysaccharide group,a single dose of lipopolysaccharide was unilaterally microinjected into the rat substantial nigra to establish the Parkinson’s disease model.Lipopolysaccharide-injected rats were treated with normal saline for 14 consecutive days.In the ginsenoside Rbl +lipopolysaccharide group,lipopolysaccharide was unilaterally microinjected into the rat substantial nigra.Subsequently,ginsenoside Rbl was intraperitoneally injected for 14 consecutive days.To investigate the therapeutic effects of ginsenoside Rbl,behavioral tests were performed on day 15 after lipopolysaccharide injection.We found that ginsenoside Rbl treatment remarkably reduced apomorphine-induced rotations in lipopolysaccharide-treated rats compared with the lipopolysaccharide group.To investigate the neurotoxicity of lipopolysaccharide and potential protective effect of ginsenoside Rbl,contents of dopamine and its metabolites in the striatum were measured by high-performance liquid chromatography.Compared with the lipopolysaccharide group,ginsenoside Rbl obviously attenuated the lipopolysaccharide-induced depletion of dopamine and its metabolites in the striatum.To further explore the neuroprotective effect of ginsenoside Rbl against lipopolysaccharide-induced neurotoxicity,immunohistochemistry and western blot assay of tyrosine hydroxylase were performed to evaluate dopaminergic neuron degeneration in the substantial nigra par compacta.The results showed that lipopolysaccharide injection caused a large loss of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra and a significant decrease in overall tyrosine hydroxylase expression.However,ginsenoside Rb1 noticeably reversed these changes.To investigate whether the neuroprotective effect of ginsenoside Rbl was associated with inhibition of lipopolysaccharide-induced microglial activation,we examined expression of the microglia marker Iba-1.Our results confirmed that lipopolysaccharide injection induced a significant increase in Iba-1 expression in the substantia nigra;however,ginsenoside Rbl effectively suppressed lipopolysaccharide-induced microglial overactivation.To elucidate the inhibitory mechanism of ginsenoside Rb1,we examined expression levels of inflammatory mediators(tumor necrosis factor-a,interleukin-1β,inducible nitric oxide synthase,and cyclooxygenase 2)and phosphorylation of nuclear factor kappa B signaling-related proteins(IκB,IKK)in the substantia nigra with enzyme-linked immunosorbent and western blot assays.Our results revealed that compared with the control group,phosphorylation and expression of inflammatory mediators IκB and IKK in the substantia nigra of lipopolysaccharide group rats were significantly increased;whereas,ginsenoside Rbl obviously reduced lipopolysaccharide-induced changes on the lesioned side of the substantial nigra par compacta.These findings confirm that ginsenoside Rbl can inhibit inflammation induced by lipopolysaccharide injection into the substantia nigra and protect dopaminergic neurons,which may be related to its inhibition of the nuclear factor kappa B signaling pathway.This study was approved by the Experimental Animal Ethics Committee of Shandong University of China in April 2016(approval No.KYLL-2016-0148).

Umbilical cord:an unlimited source of cells differentiable towards dopaminergic neurons

Cell replacement therapy utilizing mesenchymal stem cells as its main resource holds great promise for ultimate treatment of human neurological disorders.Parkinson＇s disease（PD）is a common,chronic neurodegenerative disorder hallmarked by localized degeneration of a specific set of dopaminergic neurons within a midbrain sub-region.The specific cell type and confined location of degenerating neurons make cell replacement therapy ideal for PD treatment since it mainly requires replenishment of lost dopaminergic neurons with fresh and functional ones.Endogenous as well as exogenous cell sources have been identified as candidate targets for cell replacement therapy in PD.In this review,umbilical cord mesenchymal stem cells（UCMSCs）are discussed as they provide an inexpensive unlimited reservoir differentiable towards functional dopaminergic neurons that potentially lead to long-lasting behavioral recovery in PD patients.We also present mi RNAs-mediated neuronal differentiation of UCMSCs.The UCMSCs bear a number of outstanding characteristics including their non-tumorigenic,low-immunogenic properties that make them ideal for cell replacement therapy purposes.Nevertheless,more investigations as well as controlled clinical trials are required to thoroughly confirm the efficacy of UCMSCs for therapeutic medical-grade applications in PD.

Astrocytes protect dopaminergic neurons against aminochrome neurotoxicity

Astrocytes protect neurons by modulating neuronal function and survival.Astrocytes support neurons in several ways.They provide energy through the astrocyte-neuron lactate shuttle,protect neurons from excitotoxicity,and internalize neuronal lipid droplets to degrade fatty acids for neuronal metabolic and synaptic support,as well as by their high capacity for glutamate uptake and the conversion of glutamate to glutamine.A recent reported astrocyte system for protection of dopamine neurons against the neurotoxic products of dopamine,such as aminochrome and other o-quinones,were generated under neuromelanin synthesis by oxidizing dopamine catechol structure.Astrocytes secrete glutathione transferase M2-2 through exosomes that transport this enzyme into dopaminergic neurons to protect these neurons against aminochrome neurotoxicity.The role of this new astrocyte protective mechanism in Parkinson´s disease is discussed.

The roles of serine protease, intracellular and extracellular phenoloxidase in activation of prophenoloxidase system, and characterization of phenoloxidase from shrimp haemocytes induced by lipopolysaccharide or dopamine

We investigated the effects of lipopolysaccharide （LPS） and dopamine （DA） on the activation of the prophenoloxidase （proPO） system of Litopenaeus vannamei. LPS and DA were shown with a negative dose-dependent effect on hyalne cells （HC）, semi-granular cells （SGC）, large granular cells （LGC）, and total haemocyte count （THC）. When haemocytes were treated with LPS or DA, serine proteinase activity and intracellular phenoloxidase （PO） activity were significantly reduced, but extracellular PO activity increased significantly. These findings indicated that the reduction in haemocyte counts was mainly because of the degranulation and activation of the proPO system from semi-granule and large granule cells. The PKC inhibitor, chelerythrine, and the TPK inhibitor, genistein, had an inhibitory effect on extracellular PO activity, while serine proteinase and intracellular PO activity increased. This suggests that the LPS and DA induce the activation of proPO in haemocytes via PKC and TPK-related signaling pathways, but serine proteinase may be activated only by PKC, as the genistein effects were not statistically significant. Electrophoresis analysis revealed that POs induced by LPS or DA have the same molecular mass and high diphenolase activity. Two PO bands at 526 kDa and 272 kDa were observed in PAGE, while in the haemocyte lysate supematant （HLS）, only a 272-kDa band was observed. This band was resolved after SDS-PAGE under non-reducing and reducing conditions into two groups of POs, 166 kDa and 126 kDa, and 78.1 kDa and 73.6 kDa, respectively, suggesting that PO in L. vannamei is an oligomer, which may have different compositions intra- and extracellularly.

Exosomes derived from human umbilical cord mesenchymal stem cells alleviate Parkinson’s disease and neuronal damage through inhibition of microglia

Microglia-mediated inflammatory responses have been shown to play a crucial role in Parkinson’s disease. In addition, exosomes derived from mesenchymal stem cells have shown anti-inflammatory effects in the treatment of a variety of diseases. However, whether they can protect neurons in Parkinson’s disease by inhibiting microglia-mediated inflammatory responses is not yet known. In this study, exosomes were isolated from human umbilical cord mesenchymal stem cells and injected into a 6-hydroxydopamine-induced rat model of Parkinson’s disease. We found that the exosomes injected through the tail vein and lateral ventricle were absorbed by dopaminergic neurons and microglia on the affected side of the brain, where they repaired nigral-striatal dopamine system damage and inhibited microglial activation. Furthermore, in an in vitro cell model, pretreating lipopolysaccharide-stimulated BV2 cells with exosomes reduced interleukin-1β and interleukin-18 secretion, prevented the adoption of pyroptosis-associated morphology by BV2 cells, and increased the survival rate of SH-SY5Y cells. Potential targets for treatment with human umbilical cord mesenchymal stem cells and exosomes were further identified by high-throughput microRNA sequencing and protein spectrum sequencing. Our findings suggest that human umbilical cord mesenchymal stem cells and exosomes are a potential treatment for Parkinson’s disease, and that their neuroprotective effects may be mediated by inhibition of excessive microglial proliferation.

NSC-induced D-neurons are decreased in striatum of schizophrenia: Possible cause of mesolimbic dopamine hyperactivity

Neural stem cell (NSC) hypofunction is an etiological hypothesis of schizophrenia. Although dopamine (DA) dysfunction is also a widely accepted hypothesis, molecular background of mesolimbic DA hyperactivity has not yet been well known. Here, the author proposes “D-cell hypothesis”, accounting for molecular basis of mesolimbic DA hyperactivity of schizophrenia, by NSC hypofunction and decrease of putative NSC-induced D-cells. The “D-cell” is defined as “non-monoaminergic aromatic L-amino acid decarboxylase (AADC)-containing cell”. D-cells produce trace amines, and also take up amine precursors and convert them to amines by decarboxylation. The author reported “dopa-decarboxylating neurons specific to the human striatum”, that is, “D-neurons” in the human striatum, and decrease of striatal D-neurons in patients with schizophrenia. Trace amine-associated receptor, type 1 (TAAR1), a subtype of trace amine receptors, having a quite number of ligands such as tyramine, β-phenylethylamine (PEA) and methamphetamine, has modulating functions on monoamine neurons. It has been known that reduced binding of ligands to TAAR1 receptors on DA terminal of DA neurons of the midbrain ventral tegmental area (VTA) increased firing frequency of VTA DA neurons. In brains of schizophrenia, NSC hypofunction in the subventricular zone of lateral ventricle may cause decrease of D-neurons in the striatum and nucleus accumbens, and may result in decrease of trace amine signals. Decrease of trace amine signals to TAAR1 on VTA DA neurons may increase firing frequency of VTA DA neurons, and may finally cause mesolimbic DA hyperactivity. Increased stimulation to DA D2 receptors of NSCs might suppress NSC proliferation, and may induce additional mesolimbic DA hyperactivity as well as D-cell decrease. This novel theory, “D-cell hypothesis”, possibly explains mesolimbic DA hyperactivity in pathogenesis of schizophrenia.

Detecting the apoptosis of dopamine neurons with immunohistochemical staining and double-staining technique

BACKGROUND： It is proved that the onset of Parkinson disease companies with neuronal apoptosis of dopamine in substantia nigra of midbrain. Previous researches on neuronal apoptosis of dopamine were analyzed on their consecutive tissue sections with immunohistochemical single-labeling method, immunofluorescence and electron microscope, and there are significant differences.OBJECTIVE ： To observe the feasibility of neuronal apoptosis of dopamine with in situ end labeling and tyrosine-hydroxylase antibody immunohistochemical double-labeling staining technique.DESIGN ： Controlled study.SETTING： College of Pharmacology of Taishan Medical College; College of Management of Taishan Medical College. MATERIALS ： Wistar rats with 2 weeks old and of clean grade were provided by the Animal Center of Taishan Medical College. In situ end labeling kit （terminal deoxynucleotidyl transferase, mixed reactive solution of nucleotide, transfusion-POD）, monoclonal antibody of rat antibody against tyrosine hydroxylase （Boehriuser）. METHODS： The experiment was completed at the Pharmacological Laboratory of Taishan Medical College from February to December 2005. Tissue from midbrain of rats was taken out to make paraffin sections to observe the neuronal apoptosis of dopamine under microscope with in situ end labeling and tyrosine-hydroxylase antibody immunohistochemical double-labeling staining technique.MAIN OUTCOME MEASURES ： Neuronal apoptosis of dopamine with in situ end labeling and tyrosine-hydroxylase antibody immunohistochemical double-labeling staining technique. RESULTS： ① After double-labeling staining, two kinks of positive products were observed in neurons of dopamine which were suffered from apoptosis. One stained with tyrosine hydroxylase was hyacinthine, and the other stained with in situ end labeling was buffy. Cells of positive products stained with in situ end labeling shaped as strap and bend and was distributed in clustering. Cytoplasm was hyacinthine, staining was symmetrical, and cellular ecphyma was observed. Nucleus was stained vacantly which was coincidence with form of neurons of dopamine. ②Apoptosis showed strictly in cytoplasm and nucleus at the aspect of morphology. Cytoplasm stained with in situ end labeling was hardly to recognize because of the usage of double-labeling staining technique, but nucleus was still characterized by apoptosis. The behavior of positive products stained with in situ end labeling was described as following： nucleus was buffy; karyopycnosis was round and irregular; caryotin was integrated into clump which was distributed at the border of nucleus and shaped as demilune and anular; positive signals were limited in nucleus and coincidence with morphological changes of apoptosis. However, blue and positive products were observed in cytoplasm of neurons of dopamine which did not occur apoptosis, and the nucleus was not labeled. Therefore, processing apoptosis of neurons of dopamine could be recognized. CONCULSION： Double-labeling staining technique can be used to correctly reveal histological and morphological changes of neuronal apoptosis of dopamine during its onset and development.

Humanin对鱼藤酮诱导的多巴胺神经元毒性的保护作用研究

目的探讨Humanin(HN)对鱼藤酮(rotenone,Rot)诱导的多巴胺神经元毒性损伤的保护作用和机制。方法构建Rot染毒PC12细胞模型,实验设对照组、Rot染毒组、HN预处理Rot染毒组、单独HN处理组。采用ELISA检测Rot染毒细胞内外HN的含量,CCK-8法检测细胞活性,ATP检测试剂盒检测细胞内ATP含量,DCFH-DA探针检测细胞内ROS水平,Western blot分别检测线粒体自噬调控蛋白Pink1、Parkin、p-Parkin、p62、LC3,线粒体生物发生调控蛋白PGC1α和分裂/融合调控蛋白OPA1、MFN2、DRP1、p-DRP1以及抗氧化应激调控蛋白Keap1、Nrf2的表达。采用HBAD-mcherry-EGFP-LC3腺病毒转染细胞观察自噬体和自噬溶酶体的数量。结果Rot染毒组PC12细胞内HN浓度显著高于对照组(P<0.05);与对照组比较,Rot染毒组PC12细胞活性下降,ATP含量下降,ROS的生成增加,Rot染毒后PC12细胞内Pink1、p-Parkin表达升高,LC3Ⅱ/LC3Ⅰ比值升高,p62表达下降,细胞线粒体生物发生蛋白PGC1α和线粒体融合蛋白MFN2、OPA1表达下降,而线粒体分裂蛋白p-DRP1表达升高,抗氧化应激蛋白Keap1和Nrf2表达下降(P均<0.05);与对照组比较,Rot染毒组PC12细胞中自噬体和自噬溶酶体数量增多(P<0.05),而20μmol/L HN预处理可以改善Rot染毒引起的上述变化(P<0.05)。结论HN通过抑制线粒体自噬和线粒体分裂、促进线粒体生物发生和融合以及抗氧化应激,改善Rot诱导的多巴胺神经元毒性损伤。

基于贻贝仿生构建高效抗菌及良好血液相容性的聚胺-酚表面

目的赋予血液接触类材料优异的表面抗菌性能。方法受天然贻贝黏附现象的启发,通过多巴胺(Dopamine,DA)、ε-聚赖氨酸(ε-Poly-L-lysine,ε-PL)、高碘酸钠(Sodium Periodate,NaIO4)构建一种简易、快速的聚胺-酚涂层(ε-PL@PDA),同时利用ε-PL丰富的氨基质子化形成的阳离子,实现表面高效抗菌的目的。其中DA和ε-PL通过共价交联形成酚胺聚合物,酚胺共同介导基底材料黏附形成涂层。通过傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、场发射扫描电镜(SEM)、椭圆偏光、氨基定量、水接触角(WCA)等材料学表征评价ε-PL@PDA涂层的理化性能;通过菌落计数法、细菌活/死染、液体法等细菌实验评价涂层抗菌性能;通过内皮细胞黏附与增殖实验评价其细胞相容性;通过血小板黏附与激活及半体内血液循环实验验证其血液相容性。结果材料学表征结果证明,ε-PL@PDA富氨基涂层成功制备,同时ε-PL的浓度大小会影响涂层的沉积过程;细菌实验表明,ε-PL@PDA涂层具备优异的抗菌性能,当ε-PL质量浓度为3 mg/mL时,对大肠杆菌和表皮葡萄球菌的抑制率高达91%;细胞实验和血液相容性实验表明,相较于316不锈钢(316L SS),ε-PL的质量浓度为3、30 mg/mL时,涂层均不会促进细胞毒性增强、血小板黏附和激活以及血栓形成。结论ε-PL@PDA涂层能够在不影响细胞相容性和血液相容性的基础上有效提高表面抗菌能力,因此,该高效便捷且适用性强的表面抗菌策略或有助于解决临床血液接触类器械细菌感染等问题。

力竭运动及恢复期大鼠纹状体5-HT、DA及其代谢物浓度的动态变化研究

目的:观察一次性力竭运动过程及恢复期大鼠纹状体细胞外液中多巴胺(DA)和5-羟色胺(5-HT)及其代谢物浓度的动态变化规律。方法:采用活体微透析结合毛细管电泳-激光诱导技术,连续观察清醒大鼠在一次性力竭运动过程及恢复期纹状体细胞外液中酪氨酸(Tyr)、5-HT、5-羟吲哚乙酸(5-HIAA)、色氨酸(Trp)和DA浓度的动态变化。结果:大鼠纹状体细胞外液中Trp、5-HT、5-HIAA水平运动初期均未见显著变化(P>0.05),运动后期、力竭及恢复期均显著高于安静水平(P<0.05,P<0.01);DA、Tyr水平在运动后期、力竭及恢复期显著高于安静水平(P<0.05,P<0.01);DA/5-HT运动初期显著升高(P<0.05,P<0.01),运动后期出现下降趋势,力竭前15 min降至最低点,而恢复期略有回升,但运动后期、力竭及恢复期与安静状态相比均无显著差异。结论:力竭运动过程中大鼠纹状体细胞外液中DA和5-HT的动态变化具有阶段性特征,运动疲劳过程中状体内DA和5-HT两种神经递质的代谢水平均显著增强,而其中以5-HT的作用占优。

运动疲劳对大鼠黑质致密区DA能神经元电活动的影响

观察运动疲劳大鼠黑质致密区(substantia nigra zonacompacta,SNc)多巴胺(dopamine,DA)神经元自发放电特征,探讨运动疲劳产生的中枢机制。方法:采用胞外玻璃微电极技术,在体观察运动疲劳后大鼠SNc区DA神经元自发电活动的变化。结果:运动疲劳大鼠SNc区DA能神经元自发单放电频率较对照组显著降低,神经元出现了不规则放电,且爆发式放电比例明显增多,放电间隔直方图成正偏态或随机分布(AI<1),ISI和CV值均显著大于对照组。结论:运动疲劳大鼠SNc区DA能神经元电活动出现明显改变,主要特征为兴奋性和活动规律性降低。SNc和纹状体的腹外侧和背外侧区构成的黑质—纹状体DA能神经通路参与了基底神经节对运动的调节,也是运动疲劳调控的重要中枢脑区之一。

氟哌利多影响DA对吗啡成瘾大鼠痛觉的调制

目的观察多巴胺(dopamine,DA)及其DA受体拮抗剂氟哌利多对急性吗啡成瘾大鼠尾核中痛兴奋神经元(PEN)电活动的影响。方法腹腔注射递增剂量的盐酸吗啡使Wistar大鼠形成吗啡依赖。实验以电脉冲刺激大鼠坐骨神经作为伤害性痛刺激,用玻璃微电极记录尾核中PEN的放电变化。结果DA可使吗啡成瘾大鼠PEN的兴奋性降低。氟哌利多可以逆转DA对吗啡成瘾大鼠PEN的作用。结论DA对吗啡成瘾大鼠尾核中PEN有抑制作用。这种作用可以被DA受体拮抗剂阻断。

瓜蒌薤白汤对大鼠肺纤维化形成阶段造模后(14d～28d)下丘脑、海马DA、NE、5-HT的干预作用

目的:了解瓜蒌薤白汤对肺纤维化形成阶段干预作用。方法:普通级大鼠分为正常组、模型组、泼尼松组、瓜蒌薤白汤组。除正常组外均用气管内注入平阳霉素复制肺纤维化模型,造模后14d用药,28d处死后测下丘脑及海马DA、NE、5-HT。结果:模型组下丘脑NE、DA、5-HT与海马5-HT高于正常组(P<0.05);瓜蒌薤白汤组下丘脑与海马NE、DA低于模型组与泼尼松组,5-HT低于模型组而高于泼尼松组(P<0.05)。结论:瓜蒌薤白汤能抑制模型下丘脑NE、DA、5-HT及海马5-HT的升高,并能降低海马NE、DA含量。

Dysfunction of synaptic endocytic trafficking in Parkinson's disease

Parkinson's disease is characterized by the selective degeneration of dopamine neurons in the nigrostriatal pathway and dopamine deficiency in the striatum.The precise reasons behind the specific degeneration of these dopamine neurons remain largely elusive.Genetic investigations have identified over 20 causative PARK genes and 90 genomic risk loci associated with both familial and sporadic Parkinson's disease.Notably,several of these genes are linked to the synaptic vesicle recycling process,particularly the clathrinmediated endocytosis pathway.This suggests that impaired synaptic vesicle recycling might represent an early feature of Parkinson's disease,followed by axonal degeneration and the eventual loss of dopamine cell bodies in the midbrain via a"dying back"mechanism.Recently,several new animal and cellular models with Parkinson's disease-linked mutations affecting the endocytic pathway have been created and extensively characterized.These models faithfully recapitulate certain Parkinson's disease-like features at the animal,circuit,and cellular levels,and exhibit defects in synaptic membrane trafficking,further supporting the findings from human genetics and clinical studies.In this review,we will first summarize the cellular and molecular findings from the models of two Parkinson's disease-linked clathrin uncoating proteins:auxilin(DNAJC6/PARK19)and synaptojanin 1(SYNJ1/PARK20).The mouse models carrying these two PARK gene mutations phenocopy each other with specific dopamine terminal pathology and display a potent synergistic effect.Subsequently,we will delve into the involvement of several clathrin-mediated endocytosis-related proteins(GAK,endophilin A1,SAC2/INPP5 F,synaptotagmin-11),identified as Parkinson's disease risk factors through genome-wide association studies,in Parkinson's disease pathogenesis.We will also explore the direct or indirect roles of some common Parkinson's disease-linked proteins(alpha-synuclein(PARK1/4),Parkin(PARK2),and LRRK2(PARK8))in synaptic endocytic trafficking.Additionally,we will discuss the emerging novel functions of these endocytic proteins in downstream membrane traffic pathways,particularly autophagy.Given that synaptic dysfunction is considered as an early event in Parkinson's disease,a deeper understanding of the cellular mechanisms underlying synaptic vesicle endocytic trafficking may unveil novel to rgets for early diagnosis and the development of interventional therapies for Parkinson's disease.Future research should aim to elucidate why generalized synaptic endocytic dysfunction leads to the selective degeneration of nigrostriatal dopamine neurons in Parkinson's disease.

白桦提取物解热作用及对下丘脑组织中5-HT、NE、DA含量影响的实验研究

目的 :研究白桦提取物对酵母致大鼠发热的影响及对下丘脑组织中 5 HT、NE、DA含量的影响。为其解热降温机理作用提供依据。方法 :用荧光分光光度计在 365nm、385nm、32 5nm处为激发波长 ,以4 85nm、4 80nm、375nm为发射波长 ,测定 5 HT、NE、DA含量。单位以每mg鲜脑组织含 5 HT、NE、DA的ng数表示。结果 :酵母模型组大鼠体温及下丘脑组织中 5 HT、NE、DA含量均明显高于正常对照组 ,给药组大鼠给予白桦提取物后 1h体温显著下降 ,下丘脑组织中 5 HT、NE、DA含量亦明显降低。结论 :本实验结果显示 ,白桦提取物对酵母致发热大鼠有明显的解热作用 ,其解热作用与影响体温调节中枢介质 5 HT、NE、DA的含量有关。

改良6-OHDA注射法建立早期帕金森病大鼠模型

目的:改良6-羟基多巴胺(6-OHDA)立体定位注射法建立早期帕金森病(PD)大鼠模型。方法:40只雄性SD大鼠随机分为control组10只,model组30只;于手术前30 min,腹腔注射地昔帕明(25 mg/kg)及帕吉林(5 mg/kg),control组采用立体定位右侧纹状体注射生理盐水,model组注射6-OHDA;术后第3、4周采用圆筒测试及旋转测试测定大鼠的左前肢使用率和旋转速度,免疫组化方法检测黑质内酪氨酸羟化酶(TH)阳性神经元数量。结果:圆筒测试显示madel组大鼠左前肢使用率低于control组(P<0.01),旋转测试显示model组平均向左侧旋转速度(3.48圈/min),明显快于对照组(P<0.01),PD模型成功率为89.66%;免疫组化显示,model组右侧中脑黑质致密部(SNc)部位TH阳性神经元数目较control组右侧减少(44.81±2.89)%,差异有统计学意义(P<0.01),符合临床早期PD诊断标准。结论:改良的6-OHDA注射法建立早期PD大鼠模型简单易行,成功率高。

EFFECTS OF DOPAMINE,ESTRADIOL AND TESTOSTERONE ON GONADOTROPIN RELEASE FROM THE PITUITARY FRAGMENTS OF Rana rugulosa

To understand the regulatory mechanisms of gonadotropin secretion in Rana rugulosa ,this study investigated the effects of dopamine (DA),estradiol (E 2) and testosterone (T) on the in vitro release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the pituitary fragments of female Rana rugulosa using a static incubation system and radio immunoassay (RIA). The results indicated that DA at the concentration from 0 1?μmol/L to 10?μmol/L inhibited the release of LH and FSH from the pituitary fragments of sexually pre mature or hibernating individuals,and the inhibitory effects enhanced with increasing concentrations of DA. E 2 at 1?μmol/L and 10?μmol/L significantly stimulated the release of LH of sexually pre mature individuals,but inhibited their FSH release at 0 1?μmol/L to 10?μmol/L;T had no obvious effects on their FSH release,but significantly inhibited their LH release at 10?μmol/L. Neither E 2 nor T,at the concentration from 0 1?μmol/L to 100?μmol/L,had obvious effects on the release of LH and FSH of hibernating individuals. The data suggest that DA and sexual steroids may have direct regulatory actions on LH and FSH release at the pituitary level in Rana rugulosa ,and the action of sexual steroids may relate to the gonadal development stages (seasons).

神经肽Urocortin2对吗啡成瘾大鼠VTA神经元放电及DA能神经传递的影响

目的明确神经肽urocortin2(UCN2)在吗啡成瘾中抑制丘脑腹侧背盖区(ventral tegmental area,VTA)神经活动的机制。方法建立吗啡成瘾大鼠模型,采用七管微电泳方法,电泳UCN2对吗啡成瘾大鼠VTA神经元自发放电的改变,及UCN2对多巴胺(dopamine,DA)能神经元簇发放电模式的影响,明确UCN2在VTA神经元中与DA存在汇聚作用。另外,给予促皮质激素释放因子(coticortropin-releasing factor,CRF)受体阻断剂及蛋白激酶A(protein kinase A,PKA)抑制剂,明确UCN抑制吗啡成瘾中发挥关键作用。结果UCN2使82%(31/38)吗啡成瘾大鼠VTA神经元放电频率减慢,平均放电频率由微电泳前的(20.89±2.86)Hz减少到(13.66±3.93)Hz,给药前后放电频率降低具有显著性(P<0.01),UCN2抑制作用可被PKA抑制剂H89及CRF-2R阻断剂AST-2B取消。另外,微电泳UCN2可抑制吗啡成瘾大鼠VTA中DA神经元的爆发放电,AST-2B可增强DA的兴奋效应。结论 UCN2与CRF-2R结合后,通过PKA信号途径,抑制VTA内DA神经元异常放电,在吗啡类药物成瘾中发挥抑制作用,为其用于临床治疗阿片类药物成瘾提供理论依据。