左旋多巴对帕金森病大鼠脑多巴胺神经元影响的放射自显影研究

摘要 目的 了解左旋多巴治疗对帕金森病大鼠模型脑内多巴胺神经元的影响。方法 建立右侧毁损帕金森病大鼠模型,左旋多巴治疗(20mg/kg/d) 1月,并设生理盐水干预组。停药2天后,尾静脉注射99mTc-TRODAT-1 0.2ml(800μGi),2h后先采集鼠脑部DAT显像图像再处死,测定放射性计数,计算左右脑每克放射性计数值及左右之比R值。结果①假手术组大鼠多巴胺转运体对99mTc-TRODAT-1特异性放射性摄取左右两侧差异无显著性(p>0.05),图像清晰,对称分布于基底节区;②帕金森病模型组鼠的左右两侧差异有显著性(p<0.01),R值显著升高(1.419±0.187, p<0.01),损伤侧(右侧脑)放射性摄取明显减少,图像中右侧基底节区明显稀疏;③旋多巴治疗组,部分鼠损伤侧(右侧脑)放射性摄取进一步减少,R值较帕金森病模型鼠组进一步升高(1.649±0.353, p<0.05),图像中右侧基底节区更加稀疏,临床观察评分有异动症并发（60%）;而未发生异动症的大鼠其R比值则下降(1.202±0.194),右侧放射性摄取回升,图像也支持。结论 左旋多巴治疗后部分帕金森病鼠脑内多巴胺转运体的数目及功能进一步下调,对多巴胺能神经元有毒性作用,易促发异动症。但合适剂量的左旋多巴也可促进损伤的多巴胺能神经元功能恢复。 关键词 帕金森病 左旋多巴 多巴胺转运体 99mTc-TRODAT-1     

左旋多巴和多巴胺对多巴胺转运体数量和功能的影响

目的:了解左旋多巴和多巴胺对多巴胺转运体的影响.方法:通过体外永久表达大鼠多巴胺转运体(DAT)的CHO细胞(CHO/DAT,即D8细胞)的培养,采用MTT细胞活性检测和流式细胞仪观察不同剂量左旋多巴和多巴胺对D8细胞的毒性作用;利用[3H]WIN35,428结合率和[3H]DA摄取率检测DAT的数量和功能.结果:左旋多巴和多巴胺不仅对D8细胞有毒性损害,呈剂量、时间依赖(P＜0.01),还能使DAT数量明显减少,与剂量相关(P＜0.01),一定剂量的左旋多巴(200μmol/L～1 mmol/L)可增加细胞对[3H]DA的摄取,而大剂量左旋多巴(5 mmol/L)则抑制DAT的功能(P＜0.01).左旋多巴和多巴胺呈剂量依赖性地促进细胞凋亡(P＜0.01).结论:左旋多巴和多巴胺不仅对D8细胞有毒性损害,还能使DAT数量明显减少,DAT结合位点的减少比细胞活性的下降更明显.一定剂量左旋多巴可增强DAT的功能.     

左旋多巴和多巴胺对多巴胺转运体数量和功能的影响

目的 :了解左旋多巴和多巴胺对多巴胺转运体的影响。 方法 :通过体外永久表达大鼠多巴胺转运体(DAT)的CHO细胞 (CHO/DAT ,即D8细胞 )的培养 ,采用MTT细胞活性检测和流式细胞仪观察不同剂量左旋多巴和多巴胺对D8细胞的毒性作用 ;利用 [3H]WIN35 ,4 2 8结合率和 [3H]DA摄取率检测DAT的数量和功能。 结果 :左旋多巴和多巴胺不仅对D8细胞有毒性损害 ,呈剂量、时间依赖 (P <0 .0 1) ,还能使DAT数量明显减少 ,与剂量相关 (P <0 .0 1) ,一定剂量的左旋多巴 (2 0 0 μmol/L～ 1mmol/L)可增加细胞对 [3H]DA的摄取 ,而大剂量左旋多巴 (5mmol/L)则抑制DAT的功能 (P <0 .0 1)。左旋多巴和多巴胺呈剂量依赖性地促进细胞凋亡 (P <0 .0 1)。结论 :左旋多巴和多巴胺不仅对D8细胞有毒性损害 ,还能使DAT数量明显减少 ,DAT结合位点的减少比细胞活性的下降更明显。一定剂量左旋多巴可增强DAT的功能。     

卡巴拉汀联合左旋多巴对帕金森病患者脑电图及多巴胺转运体的影响

目的 探讨卡巴拉汀联合左旋多巴对帕金森病(PD)患者脑电图及多巴转运体(DAT)的影响。方法 将2017年4月-2019年3月在本院就诊的110例帕金森病患者纳入研究,按照随机双盲法分为对照组(55例)和联合组(55例); 对照组采用单药治疗,口服左旋多巴片,联合组采用卡巴拉汀联合左旋多巴治疗; 比较2组临床疗效、脑电图、多巴转运体活性、PD严重程度、平衡能力等。结果 联合组治疗总有效率较对照组高(94.55% VS 81.82%)(P<0.05)。治疗12周后联合组δ、θ频段相对功率谱平均值、PD评定量表(UP-DRS)评分均较对照组低; β1、β2频段相对功率谱平均值、Berg平衡功能量表评分均较对照组高(P<0.05); 联合组患侧、健侧DAT活性较对照组高(P<0.05)。2组不良反应总发生率比较无明显差异(P>0.05)。结论 卡巴拉汀联合左旋多巴治疗帕金森病患者的疗效确切,可有效缓解病情,改善平衡能力,并可促使脑电图趋于正常,延缓DAT活性下降     

帕金森病脑内多巴胺转运体的SPECT显像研究

多巴胺转运体是再摄取突触间隙多巴胺的功能蛋白。早期帕金森病患者的多巴胺转运体水平明显降低。对多巴胺转运体的深入研究将有助于帕金森病病因、发病机制的阐明和早期诊断。用放射性同位素标记的多巴胺转运体配体可用于它的ＳＰＥＣＴ显像。本文就常用多巴胺转运体配体恃点,ＳＰＥＣＦ显像研究方法及其意义作一综述。     

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。     

左旋多巴对帕金森病鼠行为及多巴胺神经纤维的影响

目的 了解左旋多巴对帕金森鼠行为及多巴胺神经纤维的影响。方法 采用左旋多巴和生理盐水分别治疗不同程度损伤的帕金森鼠，观察TH阳性神经纤维及神经元的表达和鼠旋转行为。结果 左旋多巴治疗的重度帕金森病鼠出现旋转行为，而中、轻度帕金森病鼠和生理盐水治疗组未出现鼠旋转行为；左旋多巴治疗的中、轻度帕金森病鼠TH阳性神经纤维表达增加。结论 左旋多巴对中、轻度帕金森病鼠有益。     

吡贝地尔对帕金森病大鼠模型脑多巴胺转运体影响的自显影研究

目的 研究常用抗帕金森药多巴胺受体激动剂吡贝地尔(泰舒达)对脑多巴胺转运体的影响。方法立体定位右侧纹状体注射6-羟多巴胺制备偏侧帕金森病大鼠模型,模型成功后予吡贝地尔灌胃治疗[30 mg/(kg·d)]5周。分4组(正常组、帕金森病模型大鼠组、帕金森病模型大鼠经吡贝地尔治疗组、帕金森病模型大鼠未治疗组)行大鼠脑多巴胺转运体田99Tcm-TRODAT-1放射自显影。图像分析得到纹状体与小腑的平均光密度值,计算并比较各组左、右两侧脑多巴胺转运体的特异性放射性摄取比值(纹状体/小脑-1)的变化。结果 正常大鼠脑多巴胺转运体对99Tcm-TRODAT-1的特异性放射性摄取比值左、右两侧无显著性差异;成为帕金森病模型后,两侧比值较正常均降低,右侧(损毁侧)降低叫显。未治疗组帕金森病模型大鼠双侧比值均较刚成模型时明显升高;经吡贝地尔治疗后,双侧比值均较未治疗组显降低,右侧(损毁侧)降低更甚。结论 长期吡贝地尔(泰舒达)治疗可能会使帕金森病模型大鼠脑多巴胺转运体的数量减少。     

左旋多巴对帕金森病鼠行为及多巴胺神经纤维的影响

目的 了解左旋多巴对帕金森鼠行为及多巴胺神经纤维的影响。方法采用左旋多巴和生理盐水分别治疗不同程度损伤的帕金森鼠,观察TH阳性神经纤维及神经元的表达和鼠旋转行为。结果 左旋多巴治疗的重度帕金森病鼠出现旋转行为,而中、轻度帕金森病鼠和生理盐水治疗组未出现鼠旋转行为;左旋多巴治疗的中、轻度帕金森病鼠TH阳性神经纤维表达增加。结论 左旋多巴对中、轻度帕金森病鼠有益。     

脑多巴胺转运体SPECT显像鉴别早期帕金森病与原发性震颤

目的探讨脑多巴胺转运体99mTc-TRODAT-1 SPECT显像在鉴别帕金森病与原发性震颤的应用.方法 19例帕金森病与17例原发性震颤患者均行脑多巴胺转运体99mTc-TRODAT-1 SPECT显像,勾画出两组患者脑内感兴趣区(双侧纹状体及小脑),计算机自动给出各区的放射性计数,计算左、右侧纹状体的特异性放射性摄取比值及不对称指数并加以比较.结果帕金森病患者的Hoehn-Yahr分期是1.7±0.6.原发性震颤患者脑多巴胺转运体对99mTc-TRODAT-1的特异性摄取比值左(0.5±0.1)、右(0.6±0.2)两侧差异无显著意义;而帕金森病患者症状对侧(0.3±0.2)与症状同侧(0.4±0.2)差异有显著意义, 症状对侧低, 症状同侧高,并且双侧均低于原发性震颤患者.不对称指数帕金森病患者(21.1±17.4)明显高于原发性震颤(9.2±11.2)患者.结论脑多巴胺转运体99mTc-TRODAT-1 SPECT显像可以鉴别帕金森病与原发性震颤.     

Normal dopamine transporter binding in dopa responsive dystonia

We report the clinical manifestations of dopa responsive dystonia (DRD) in 2 patients from the same family. The brain magnetic resonance images (MRI) were normal. The dopamine transporter (DAT) imaging with ^99mTc-TRODAT-1 was performed in the 2 probands, 8 patients with young onset Parkinson disease (YOPD) and 16 normal controls. The ratios of ^99mTc-TRODAT-1 brain SPECT in the striatum were 2.40 ± 0.12 (right) and 2.30 ± 0.17 (left) in these 2 DRD patients as compared with 1.38 ± 0.18 (right), 1.41 ± 0.20 (left) in YOPD patients, and 2.15 ± 0.35 (right), 2.14 ± 0.32 (left) in normal controls respectively. A normal DAT uptake was found in DRD suggesting a normal presynaptic nigrostriatal dopaminergic terminal. We conclude that a normal DAT in parkinsonian patients can differentiate DRD from YOPD. In addition, DAT with ^99mTc-TRODAT-1 is a reliable and convenient tool to study the function of the presynaptic dopaminergic axonal terminals. Received: 18 October 2001 Received in revised form: 1 February 2002 Accepted: 6 February 2002     

复方地黄方干预帕金森病药物左旋多巴毒副反应大鼠纹状体多巴胺转运体含量的变化

Long-term application of levodopa (L-3,4-dihydroxyphenylalanine,L-DOPA) for Parkinson’s disease can lead to adverse effects and reduce the amount of dopamine transporter (DAT) in the corpus striatum.The present study attempted to verify whether increasing the amount of DAT can reduce the adverse effects of L-DOPA.The specific radioactive uptake value of DAT in the corpus striatum of the lesioned hemisphere was significantly decreased,but was significantly increased following administration of compound rehmannia formula [Radix rehmanniae preparata (prepared rehmannia root),Concha margaritifera usta (nacre),Radix paeoniae alba (white peony alba),Radix salviae miltiorrhizae (Danshen root),Scorpio (scorpion),green tea] for 4 weeks.The changes in DAT 125I-beta-carbomethoxy-3 beta-(4-iodophenyl) tropane autoradiography were consistent with those in radioactivity.The results revealed that the compound rehmannia formula can reduce the adverse effects of L-DOPA in treating Parkinson’s disease,possibly by increasing the amount of DAT.     

Pharmacological characterization and anatomical distribution of the dopamine transporter in the mouse cerebellum

We studied the binding parameters, the pharmacological profile and the anatomical distribution of the dopamine transporter in the mouse cerebellum by using the specific dopamine uptake antagonist [³H]GBR12935 and an antidopamine transporter monoclonal antibody. Competition experiments in cerebellar and striatal membrane preparations showed that [³H]GBR12935 binds to a specific binding site, sensitive to dopamine and low concentrations of mazindol. The affinity of dopamine for the cerebellar binding site was one order of magnitude lower than the affinity for the striatal binding site. Saturation experiments in cerebellar membrane preparations and thin frozen sections showed that the affinity of [³H]GBR12935 for this binding site is similar to its affinity for the striatal dopamine transporter. Saturable binding was lobule specific and in general was higher in the molecular layer compared to the granule cell layer. The immunohistochemical signal was mostly concentrated in the Purkinje cell layer and the cerebellar nuclei. The results suggest that the cerebellar dopamine transporter is similar but not identical to the striatal dopamine transporter and that it is present in the mouse cerebellum in a lobule and lamina specific pattern.     

Nigrostriatal cell firing action on the dopamine transporter

The influence of nigrostriatal cell firing on the dopamine transporter (DAT) activity of the rat striatum was studied in vivo with amperometric methods. Data were obtained after preventing dopamine (DA) release with alpha-methyl-L-tyrosine and replenishing extracellular DA with local injections. The DA cell stimulation, which under basal conditions increased extracellular DA, decreased DA after this pre-treatment, suggesting that firing activity facilitates the DA cell uptake of DA under these circumstances (drain response). Cocaine and GBR13069 markedly decreased the drain response, suggesting that it is dependent on DAT activation. Data obtained after haloperidol and apomorphine administration showed that the drain response was facilitated by pre-synaptic DA receptor stimulation but that receptors are not a necessary requirement. Two components in the drain response were observed, one with a short latency and duration that needed high-frequency stimuli, and the other with a long latency and duration that was even induced by low-frequency stimuli. This is the first evidence showing that DAT can be activated by the firing activity in nigrostriatal cells in a direct way and without the participation of pre-synaptic DA receptors.     

Effects of levodopa on dopaminergic neurons and induced dyskinesia A radio-imaging study

BACKGROUND: Radio-imaging has been used in neurological diagnosis,in particular for extrapyramidal disease.Moreover,it has been extensively utilized for early diagnosis of Parkinson’s disease (PD) patients and in animal studies.However,it has rarely been utilized to assess drug-induced side effects in PD.OBJECTIVE: To investigate changes in dopamine transporter expression in a rat model of PD through the use of radio-imaging taking 99mTc-TRODAT-1 as an imaging agent,and to explore the effect of levodopa (L-...     

Studies of the biogenic amine transporters. VIII: identification of a novel partial inhibitor of dopamine uptake and dopamine transporter binding

Using [125I]RTI-55 to label the dopamine transporter (DAT), our laboratory has consistently detected one binding site as well as one component of [3H]DA uptake. We report here the identification of a novel partial inhibitor of [3H]DA uptake and DAT binding (SoRI-9804). [125I]RTI-55 binding to the DAT (mouse caudate, rat caudate, HEK cells expressing the cloned DAT), the 5-HT transporter (rat brain), and [3H]DA uptake (rat caudate synaptosomes) were conducted using published procedures. 4-[(Diphenylmethyl)amino]-2-phenylquinazoline (SoRI-9804) was essentially inactive at SERT binding and resolved two DAT binding components in all three tissues, having high affinity (mean Ki of 465 nM) for about 40% of the binding sites and an essentially immeasurable Ki (> 100 microM) for the remaining 60% of the binding sites. The [3H]DA uptake experiments indicated that about 50% of uptake was SoRI-9804-sensitive. Saturation binding experiments showed that SoRI-9804 competitively inhibited [125I]RTI-55 binding to the SoRI-9804-sensitive binding component. To determine if the two binding sites discriminated by SoRI-9804 were regulated by the MAP kinase pathway, rat caudate synaptosomes were incubated in the absence or presence of 10 microM of PD98059, which inhibits activation of the MAP kinase pathway. The results indicated that inhibition of MAPK/ERK kinase decreased the total B(max) of the DAT by 90%. Treatment with PD98059 increased the proportion of the SoRI-9804-sensitive binding component from 68-80% of the total B(max). The PD98059 experiments suggest that inhibition of MAP kinase cannot explain the differential interaction of SoRI-9804 with the DAT. Viewed collectively, the present results indicate that SoRI-9804 discriminates two components of the DA transporter. Further studies will be needed to determine the underlying mechanism of this effect and if partial inhibition of DA uptake results in any unique behavioral effects.     

Direct approach for attenuating cocaine's effects on extracellular dopamine: Targeting the dopamine transporter

Using in vivo microdialysis techniques, the effects of RTI-55 and/or cocaine on extracellular dopamine (DA) concentrations were measured in the nucleus accumbens (NACC) of freely moving rats. In control animals, cocaine (20 mg/kg) increased NACC DA approximately 458% 60 minutes following administration, returning to baseline values within 200 minutes. Similarly, RTI-55 administration (0.25 mg/kg) increased NACC DA levels approximately 347%. When combined, however, cocaine further increased NACC DA to 705% of baseline values when given 4 hours following RTI-55. This increase was significantly larger than cocaine alone (P < 0.05). In addition, chronic RTI-55 administration (5 days) further potentiated cocaine's ability to increase NACC DA (783%) but this did not reach statistical significance (P > 0.1) compared to acute RTI55/cocaine animals. These findings indicate that RTI-55, a drug that binds directly to the dopamine transporter (DAT) with higher affinity than cocaine, does not appear to be effective in attenuating cocaine's effects on NACC dopamine levels. In fact, acute RTI-55 potentiates cocaine's effects on NACC DA. Synapse 26:423–427, 1997. Published 1997 Wiley-Liss, Inc. This article is a US government work and, as such, is in the public domain of the United States of America.     

An interaction between the serotonin transporter promoter region and dopamine transporter polymorphisms contributes to harm avoidance and reward dependence traits in normal healthy subjects

Summary. There is evidence for an association between polymorphisms of serotonin- and dopamine-related genes and temperamental personality traits. Recent findings have shown that interactions between allelic variants of the different genes may contribute to personality traits. We examined the effects of serotonin transporter-linked promoter region (5-HTTLPR) and dopamine transporter (DAT1) gene polymorphisms for associations with the Temperament and Character Inventory (TCI) temperament subscales in 209 Koreans. We found that the variants of 5-HTTLPR interacted with the DAT1 gene polymorphism to influence the HA and RD temperament subscales of TCI. Neither of these two genes affected any subscales of TCI alone. Controlling for the effects of gender and age, we found significant interactions between 5-HTTLPR and DAT1 genes on Harm Avoidance (HA) and Reward Dependence (RD) as measured by the TCI (Hotelling’s Trace = 3.0, P = 0.02). In the presence of the DAT1 10/10 genotype, subjects of group L of 5-HTTLPR had a significantly higher HA score and significantly lower RD score than those of group S (F = 5.04, df = 1, p = 0.03 and F = 8.35, df = 1, p = 0.004, respectively). These findings suggest that the variants of 5-HTTLPR interacted with the DAT1 gene polymorphism to influence the HA and RD temperament subscales of TCI.