不同剂量左旋多巴对正常大鼠黑质细胞作用的研究

目的　研究不同剂量左旋多巴对正常大鼠黑质细胞作用 ,探讨左旋多巴合理治疗帕金森病的方法。方法　采用TUNEL、Nissl染色 ,电镜观察手段 ,观察小、中、大 3种不同剂量 [10mg/(kg·d)、5 0mg/(kg·d)、2 0 0mg/(kg·d) ]左旋多巴 ,不同作用时间 (1天、7天、14天 )对正常大鼠黑质细胞作用。结果　对照组 ,小、中剂量左旋多巴给药组黑质细胞凋亡数 ,黑质细胞超微结构 ,尼氏细胞数无显著差异 ;大剂量给药组大鼠黑质细胞数随着左旋多巴使用时间、剂量的增加而增加 ,尼氏细胞则随左旋多巴使用时间、剂量增加而减少。结论　大剂量左旋多巴对正常大鼠黑质细胞有神经毒性作用 ,临床用左旋多巴宜尽可能小剂量     

不同剂量左旋多巴对帕金森病大鼠行为学影响

目的观察不同剂量左旋多巴治疗帕金森病（PD）的效果,并进一步探讨合理使用左旋多巴治疗PD的剂量。方法采用6-OHDA脑立体定向注射术建立大鼠PD模型,采用行为学观察法观察3种不同剂量左旋多巴[按体重10、50、100mg/（kg.d）]作用不同时间（1、3、5、7d）对PD大鼠黑质细胞毒性作用后的行为学变化以及停止左旋多巴治疗后7d各项指标的变化。结果与对照组比较,小剂量组大鼠旋转圈数随左旋多巴使用剂量和时间增加而减少,中、大剂量组大鼠旋转圈数随左旋多巴使用剂量和时间增加而增加;各组大鼠旋转启动时间随左旋多巴使用剂量和时间增加而减少,最高转速及持续时间则随使用剂量增加而增加。结论应尽可能以小剂量、间隔使用左旋多巴治疗PD。     

不同剂量左旋多巴对帕金森病运动并发症大鼠模型行为学的影响

目的：比较不同剂量左旋多巴长期注射对帕金森病（PD）运动并发症大鼠模型异常不自主运动（AIM）和疗效减退的影响,以确定合适的左旋多巴用药剂量和行为学评价标准。方法：立体定向SD大鼠右侧前脑内侧束,注射6羟基多巴建立PD大鼠模型。成模PD大鼠随机分为3组,分别腹腔注射左旋多巴酯：小剂量组（20mg·kg（-1）·d（-1））、中剂量组（50mg·kg（-1）·d（-1））和大剂量组（100mg·kg（-1）·d（-1））,每天2次,持续21d。比较3组PD大鼠模型AIM各组份的评分情况及对侧旋转反应时间。结果：左旋多巴3种剂量均可诱发PD大鼠出现相似程度的口面、前肢、轴向AIM,但大剂量组大鼠旋转AIM的评分高于小剂量组（P〈0.05）,且旋转反应时间缩短幅度大于中剂量组和小剂量组（P〈0.05）。结论：小剂量左旋多巴就可诱发PD大鼠出现明显的AIM,又能避免过于剧烈的旋转运动对AIM评分的干扰;但观察疗效减退现象需要选用大剂量左旋多巴以诱导出稳定下降的旋转反应时间。     

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。     

左旋多巴诱发异动症大鼠纹状体区P38及GAP-43表达的变化

目的　观察帕金森病(Parkinson disease, PD)大鼠经慢性间断性左旋多巴(levodopa,L- dopa)治疗后纹状体区域突触功能的变化。方法　 6 羟多巴胺 (6 OHDA)脑立体定位注射制备偏侧PD大鼠模型,复方L dopa甲酯治疗4周[按体重20 mg/(kg·d),分2次进行腹腔注射]建立异动症(levodopa induced dyskinesias,LID)大鼠模型,采用免疫组化方法检测 PD组和 LID组纹状体内突触素(synaptophysin, P38)及生长相关蛋白(growth associated protein, GAP 43)的表达。结果　 PD 大鼠损毁侧 P38 免疫反应阳性颗粒的数密度[(0. 002 1±0 000. 5)个/μm2]和面密度(0. 045±0.01)均明显高于健侧[分别为(0 .015 0±0. 000 6)个/μm2, (0 027±0 .009)](P<0 .01),GAP- 43阳性颗粒面密度(0. 015±0. 000 3)高于健侧(0. 01±0 .000 27)(P<0. 05);LID大鼠经L dopa治疗后两者表达进一步增多,与PD组大鼠损毁侧相比差异有显著性(均 P<0 .05)。结论　慢性L dopa治疗进一步促进了PD大鼠纹状体区域P38及GAP -43的高表达,可能涉及皮质纹状体病理性长时程增强的突触前机制,提示皮质 纹状体环路的突触可塑性与LID发生密切相关。     

左旋多巴对帕金森病大鼠毒性作用的实验研究

目的　研究左旋多巴 (L dopa)对帕金森病 (PD)模型大鼠异常行为、黑质抗氧化系统、线粒体呼吸链功能和神经递质代谢的影响及其机制。方法　应用 6 羟基多巴胺 (6 OHDA)立体定向注射制作PD大鼠模型 ,给PD大鼠L dopa 2 5mg/ (kg·d)灌胃 ,共 4 5d。给药前后分别进行行为学测试 ,给药后测定黑质区谷胱甘肽过氧化物酶 (GSH Px)、丙二醛 (MDA)、活性氧 (ROS)及线粒体呼吸链酶复合体Ⅰ水平 ,测定尾状核头部多巴胺 (DA)、高香草酸 (HVA)、单胺氧化酶 B(MAO B)的水平。结果　 (1)L dopa组大鼠旋转速度给药前为(13.1± 1.5 )r/min ,给药后为 (7.2± 1.6 )r/min,给药前后比较差异有显著性 (P <0 .0 1) ;(2 )L dopa组GSH Px活性、呼吸链酶复合体Ⅰ水平降低 ,MDA含量、ROS活性升高 ,与对照组比较差异均有显著性 (均P <0 .0 1) ;(3)L dopa组MAO B活性、DA、HVA含量及DA/HVA比值与对照组比较均显著升高 (P <0 .0 5～ 0 .0 1)。结论L dopa能有效改善PD大鼠的旋转行为 ,但可加重黑质区氧化应激损伤 ,抑制线粒体呼吸链酶活性。     

恩他卡朋对帕金森病大鼠的疗效

目的:观察恩他卡朋与左旋多巴/苄丝肼(美多芭)联用对帕金森病大鼠的治疗作用。方法:6-羟多巴(6-OHDA)毁损内侧前脑束(MFB)建立SD大鼠PD模型。成模大鼠腹腔注射不同剂量的美多芭与恩他卡朋,观测大鼠旋转圈数和持续时间。结果:单用恩他卡朋不能诱导PD大鼠旋转。采用美多芭(6.25、12.5mg·kg-1)和不同剂量的恩他卡朋(10、5、0mg·kg-1)联用的PD大鼠,旋转圈数明显增加、旋转时间也明显延长;恩他卡朋的剂量越大,旋转运动的持续时间越长,但出现旋转反应高峰的时间向后推迟。结论:足量的恩他卡朋可以加强左旋多巴的疗效,半量的恩他卡朋疗效欠佳。     

阳离子脂质体介导AADC基因重组体脑内直接注射治疗帕金森病的实验研究

目的　探讨芳香族氨基酸脱羧酶 (AADC)基因脑内移植对帕金森病的治疗作用及其在左旋多巴 (L dopa)治疗过程中的地位 ,并探讨阳离子脂质体介导的基因治疗方法的有效性。 方法　实验组与对照组分别以 pCDNA3 AADC重组体和 pCDNA3空载体进行阳离子脂质体包裹后 ,注射于帕金森病SD大鼠纹状体内 ,观察两组大鼠旋转行为的改善 ;并在该基础上对两组大鼠分别采用一定浓度的L dopa进行治疗 ,观察脑内移植AADC基因后对大鼠旋转行为的进一步改善。采用免疫组化方法确定AADC的表达。结果　 (1 )阳离子脂质体包裹的pCDNA3 AADC重组体脑内注射后 ,在 3、7、1 4、2 1、2 8d时大鼠的旋转行为获得了一定的改善 (P <0 0 5) ,分别改善 56 0 % ,62 6 % ,49 4% ,36 3 % ,2 7 4% ,以第 1周时最为明显 ,在第 5周时 ,其旋转行为则与移植前差异无显著意义 (P >0 0 5) ;(2 )使用同等浓度的左旋多巴 (L dopa ,1 0mg·kg- 1 ·d- 1 )治疗后 ,在上述相同的时间点时 ,实验组较对照组明显改善模型大鼠的旋转行为 (P <0 0 5) ,以第 1周时最为明显 ,其旋转行为改善达93 4% ,在第 5周时 ,两组间差异无显著意义 (P >0 0 5) ;(3)免疫组化方法确定AADC在纹状体区的稳定表达。结论　增加脑内AADC基因的表达可有效改善帕金森病大鼠的旋转行     

人参再造丸对帕金森病鼠模型旋转行为的影响

目的观察人参再造丸对帕金森病(PD)鼠模型的旋转行为的影响.方法将6-羟基多巴胺用立体定向法注入大鼠一侧中脑被盖腹侧区制作PD大鼠模型,并分为对照组、美多巴组、人参再造丸组、人参再造丸与美多巴联合组4组,由阿朴吗啡诱发PD鼠旋转行为,观察各组15d、1月、2月、3月旋转圈数,2个月时启动时间、最高转速及持续时间等.结果人参再造丸组旋转圈数随时间延长下降明显,2个月时行为学改善尤为显著;人参再造丸联合小剂量美多巴组15d旋转圈数即有下降,并随时间延长下降显著.结论人参再造丸联合小剂量美多巴治疗PD,不仅起效迅速,且疗效持久,不良反应小.     

人参再造丸对帕金森病鼠模型旋转行为的影响

目的 观察人参再造丸对帕金森病(PD)鼠模型的旋转行为的影响。方法 将6-羟基多巴胺用立体定向法注入大鼠一侧中脑被盖腹侧区制作PD大鼠模型，并分为对照组、美多巴组、人参再造丸组、人参再造丸与美多巴联合组4组，由阿朴吗啡诱发PD鼠旋转行为，观察各组15d、1月、2月、3月旋转圈数，2个月时启动时间、最高转速及持续时间等。结果 人参再造丸组旋转圈数随时间延长下降明显，2个月时行为学改善尤为显著；人参再造丸联合小剂量美多巴组15d旋转圈数即有下降，并随时间延长下降显著。结论 人参再造丸联合小剂量美多巴治疗PD，不仅起效迅速，且疗效持久，不良反应小。     

Dose-related effects of continuous levodopa infusion in rats with unilateral lesions of the substantia nigra

Preclinical studies in rats have demonstrated markedly different effects of intermittent and continuous levodopa administration on many biochemical and functional parameters yet the dose regimens employed have not been fully evaluated. In this study, rats with unilateral 6-hydroxydopamine nigral lesions were administered levodopa (0–1200 mg/kg/day) and benserazide (25 mg/kg/day) subcutaneously via osmotic minipump and studied 20–22 h later for rotational behavior, striatal dopamine concentration, and regional cerebral glucose utilization (RCGU). Levodopa infusion at 100 mg/kg/day resulted in minimal rotation and minimal striatal dopamine replacement but did increase RCGU in the subthalamic nucleus and decrease RCGU in the lateral habenula, consistent with a selective inhibition of the striatopallidal GABAergic (indirect striatal output) pathway. Levodopa infusion at 100 mg/kg/day did not significantly increase RCGU in the entopeduncular nucleus (EP) and substantia nigra pars reticulata (SNr), as does the acute injection of levodopa (25–50 mg/kg), indicating that this levodopa dose elicits only part of the spectrum of metabolic effects elicited by acute levodopa injection. Higher doses of levodopa (400–1200 mg/kg/day) resulted in moderate rates of rotation, dose-dependent increases in striatal dopamine, and increased RCGU in the EP and SNr, consistent with activation of the striatonigral GABAergic (direct striatal output) pathway. In the EP and SNr, the two major output nuclei of the basal ganglia, levodopa infusion at 800 and 1200 mg/kg/day reproduced the metabolic effects elicited by acute injection of levodopa. These results demonstrate, for the first time, dose-dependent effects of levodopa on distinct populations of striatal output neurons which may be relevant to the pathogenesis of levodopa-induced dyskinesias in Parkinson's disease. The minimal dopamine replacement and partial functional effects elicited by levodopa infusion at 100 mg/kg/day indicate the need for caution in the interpretation of prior studies of continuous levodopa infusion which employed this dose.     

帕金森病大鼠模型的实验研究

目的 观察帕金森病（PD）大鼠模型行为学变化特点。方法 通过改良PD大鼠模型，观察30只大鼠模型成功后1、7、14天旋转行为的多项指标变化，如：启动时间、持续时间、最高转速、旋转圈数等。结果 1－14天时PD大鼠启动时间逐渐延长、持续时间逐渐缩短，最高转速与旋转圈数不变。结论 改良PD大鼠模型制作方法科学、简单、定位可靠；PD大鼠最高旋转速度、旋转圈数能反映黑质损伤程度。     

帕金森病行为学和黑质形态学实验研究

目的观察帕金森病大鼠行为学及其形态学特点。方法本试验通过PD大鼠模型,采用行为学观察、TUNEL法、HE染色、Nissl染色及电镜方法,观察模型成功后1d、7d、14d PD大鼠行为、形态学变化。结果 PD大鼠旋转圈数无明显变化,凋亡细胞、尼氏细胞逐渐减少,超微结构损伤逐渐加重。结论 PD大鼠旋转行为变化有其病理学基础。     

Bradykinin receptor agonist facilitates low-dose cyclosporine-A protection against 6-hydroxydopamine neurotoxicity

Cyclosporine-A (CsA) is neuroprotective in animal models of Parkinson's disease (PD), Huntington's disease and stroke. Because CsA does not easily cross the blood-brain barrier (BBB), high doses (i.e. >10 mg/kg in rats) and chronic administration may be necessary to produce beneficial effects. However, immunosuppressant side effects (including nephrotoxicity and hepatotoxicity) are associated with such CsA dosing regimens. The bradykinin B2 receptor agonist, Cereport (labradimil and formerly called RMP-7), transiently increases the permeability of the BBB to facilitate delivery of drugs to the CNS. Here we examined the effects of co-administration of CsA and Cereport in the unilateral 6-OHDA model of PD. Animals were pretreated with vehicle, CsA alone (1 mg/kg, a low dose without either immunosuppressive or neuroprotective effects, or 10 mg/kg, a high dose that produces both immunosuppression and neuroprotection), or CsA (1 mg/kg) in combination with Cereport (9 microg/kg). Behavioral analyses, using elevated body swing and amphetamine-induced rotational tests, revealed that a low dose of CsA was neuroprotective when combined with Cereport, but not when given alone. Tyrosine hydroxylase immunohistochemistry demonstrated that while near complete (>90%) depletions of nigral TH-ir neurons were noted in lesioned animals that received vehicle infusion or low-dose CsA alone, lesioned animals that received low-dose CsA+Cereport exhibited a significant sparing of nigral TH-ir neurons and a marked reduction in the loss of striatal TH-ir fibers. The safer and effective administration of lower doses of CsA combined with enhanced BBB permeability using Cereport, offers a novel way of producing protective effects in the CNS without the toxic liabilities of high-dose CsA.     

Relationships between various behavioural abnormalities and nigrostriatal dopamine depletion in the unilateral 6-OHDA-lesioned rat

While rotational asymmetry is used as a characteristic behavioural sign of striatal dopamine (DA) loss in unilateral animal models of Parkinson's disease (PD), there is relatively little analysis of how other common behavioural deficits relate to nigrostriatal DA depletion. We analysed the relationships between several deficits induced by unilateral 6-OHDA lesions and striatal neurochemistry, as well as neuronal loss in the dopaminergic substantia nigra (SN). Behaviour was evaluated from before until 6 weeks after surgery and abnormalities appeared in body axis, head position and sensorimotor performance as well as apomorphine-induced rotation. As expected, rotational behaviour correlated with striatal DA loss and not with other striatal neurotransmitters measured. Similar observations were found for sensorimotor deficits ('disengage task'). Both deficits were observed in rats with >70% loss of TH+ nigral neurons and >80% loss of striatal DA. Additional postural abnormalities appeared with mean losses of 87% of nigral DA neurons and 97% striatal DA, consistent with observations in patients with advanced PD. The data show that the repertoire of behavioural abnormalities manifested by hemiparkinsonian rats relate directly to the degree of nigrostriatal DA loss and, therefore, mimic features of PD. Analysis of such behaviours are relevant for chronic therapeutic studies targeting PD.     

Simultaneous microdialysis in striatum and substantia nigra suggests that the nigra is a major site of action of L-dihydroxyphenylalanine in the "hemiparkinsonian" rat.

L-DOPA is frequently used to relieve symptoms of Parkinson's disease (PD), but its use in patients with more advanced PD is complicated by on-off phenomena. We used simultaneous microdialysis of striatum and ipsilateral substantia nigra to characterize changes in extracellular fluid (ecf) levels of dopamine (DA) following systemic treatment with L-DOPA (25 mg/kg as methylester) in awake, normal rats and those with partial (less than 99%) or complete (greater than 99%) DA depleting unilateral lesions of the nigrostriatal pathway (nsp). In normal rats, nigral ecf DA rose 17-fold above baseline after L-DOPA, compared to a 2.6-fold increase in normal striata. Striatal ecf DA rose equally after L-DOPA in all three groups, whereas peak nigral ecf DA in completely lesioned rats was three times that in normal or partially lesioned animals. Peak nigral ecf DA in completely lesioned rats exceeded striatal ecf DA in all groups by almost 2-fold. Activity after L-DOPA was biphasic ("hyperkinetic/bradykinetic") in completely lesioned but not in normal or partially lesioned animals, and the reduced activity occurred 2.5-4 h after L-DOPA at a time when both nigral and striatal ecf DA levels were still elevated. L-DOPA-induced increases in activity were predictable by greater elevations in nigral compared to striatal ecf DA in animals with complete lesions of the nigrostriatal pathway. Post-DOPA reduced activity might result from desensitization of synaptic events mediated by DA receptors; this may underlie DOPA-related on-off phenomena in patients with advanced PD.     

Chronic nicotine treatment counteracts the disappearance of tyrosine-hydroxylase-immunoreactive nerve cell bodies, dendrites and terminals in the mesostriatal dopamine system of the male rat after partial hemitransection

Male Sprague-Dawley rats were partially hemitransected at the mesodiencephalic junction and treated with nicotine (nicotine hydrogen (+)-tartrate) using Alzet minipumps implanted subcutaneously. Nicotine was delivered for 2 weeks in a dose of 0.125 mg/kg/h resulting in a serum nicotine level of 50.0 +/- 5.1 ng/ml. Three other groups of rats were analyzed: hemitransected rats receiving saline treatment and sham-operated animals receiving nicotine and saline, respectively. The effects of hemitransection and nicotine rostrally as well as caudally to the lesion were evaluated with image analysis of tyrosine hydroxylase (TH)-immunoreactive (IR) nerve cell body and dendrite profiles in the rostral and caudal substantia nigra and of TH-IR nerve terminal profiles in the striatum. Adjacent sections were taken to Nissl staining. [3H]Nicotine binding in the midbrain and forebrain was studied by means of receptor autoradiography on partially hemitransected rats receiving no treatment. Catecholamine (CA) levels in the frontal cortex were measured using high-performance liquid chromatography (HPLC). Striatal dopamine (DA) function was analyzed studying apomorphine-induced (1.0 mg/kg) ipsilateral rotational behavior. The spontaneous behavior of the rats was evaluated with a hole board. Furthermore, body temperature and body weight were measured. The results demonstrated a lesion-induced disappearance of TH-IR cell body and dendrite profiles in the substantia nigra and of TH-IR nerve terminal profiles in the striatum. Similar findings were seen after Nissl staining. A significant counteraction of this disappearance was found in the nicotine-treated animals. On the lesioned animals a marked reduction of [3H]nicotine binding in the striatum and the substantia nigra was found. In the functional experiments an enhancement of the apomorphine-induced ipsilateral rotational behavior was demonstrated. The degree of rotation was positively correlated with the serum nicotine level. The study on spontaneous activity in the hole board showed a slower restoration of total activity in the hemitransected nicotine-treated rats. All these results are compatible with the hypothesis that the protective action of nicotine on the mesostriatal DA system may be due to a desensitization of excitatory nicotine cholinoceptors located on the nigral DA nerve cells, leading to a reduction of firing rate and reduced energy demands. Such an action of nicotine could be of importance for a possible anti-parkinsonian effect.     

Dopamine-nociceptin/orphanin FQ interactions in the substantia nigra reticulata of hemiparkinsonian rats: involvement of D2/D3 receptors and impact on nigro-thalamic neurons and motor activity

Nociceptin/orphanin FQ (N/OFQ) peptide (NOP) receptor antagonists proved to be effective in alleviating experimental parkinsonism. Nonetheless, loss of effectiveness or even worsening of parkinsonian symptoms have been observed at high doses. With the aim of clarifying the circuitry underlying the dual action of NOP receptor antagonists and the role of endogenous dopamine, the NOP receptor antagonist 1-benzyl-N-[3-[spiroisobenzofuran-1(3H),4′-piperidin-1-yl]propyl]pyrrolidine-2-carboxamide (Compound 24) and the D₂/D₃ receptor antagonist raclopride were used in 6-hydroxydopamine hemilesioned rats. Systemically administered Compound 24 improved motor activity in the 0.1–10 mg/kg dose range being ineffective at 30 mg/kg. To confirm NOP selectivity, Compound 24 improved motor performance in wild-type mice at 1 and 10 mg/kg and inhibited it at 60 mg/kg, being ineffective in NOP receptor knockout mice. To prove that the bell-shaped profile was mediated by nigral NOP receptors, reverse dialysis of Compound 24 (0.03 μM) in substantia nigra reticulata ameliorated akinesia whereas Compound 24 (3 μM) was ineffective. To demonstrate that motor responses were mediated by tuning inhibitory and excitatory inputs to nigro-thalamic neurons, the low concentration elevated GABA and reduced glutamate in substantia nigra, simultaneously reducing GABA levels in ventro-medial thalamus. Conversely, the higher concentration reduced nigral and elevated thalamic GABA, without affecting nigral glutamate levels. Co-perfusion with raclopride (1 μM) abolished the antiakinetic action of Compound 24 (0.03 μM) and turned the ineffectiveness of Compound 24 (3 μM) into an antiakinetic effect. The low concentration reduced nigral but did not affect thalamic GABA whereas the higher concentration elevated nigral and reduced thalamic GABA. Neither concentration affected nigral glutamate. We conclude that dual motor effects of Compound 24 in hemiparkinsonian rats are accomplished through blockade of nigral NOP receptors resulting in opposite modulation of nigro-thalamic neurons. Endogenous dopamine contributes to these responses affecting the level of GABAergic inhibition of the nigral output via D₂/D₃ receptors.     

神经节苷脂对帕金森病鼠旋转行为、纹状体多巴胺浓度及黑质病理的影响

目的观察神经节苷脂对帕金森病（Ｐａｒｋｉｎｓｏｎｄｉｓｅａｓｅ，ＰＤ）鼠模型的旋转行为、纹状体多巴胺浓度及黑质病理的影响。方法将６－羟基多巴胺用立体定向法注入大鼠一侧中脑被盖腹侧区制作ＰＤ大鼠模型，并于同侧侧脑室注射混合型神经节苷脂（ａｍｉｘｅｄｇａｎｇｌｉｏｓｉｄｅｐｒｅｐａｒａｔｉｏｎ，ＧＭ），观察ＧＭ对由阿朴吗啡所诱发的旋转行为、受损侧纹状体多巴胺浓度及黑质病理的影响。结果ＧＭ能减轻ＰＤ大鼠模型的旋转行为、使受损侧纹状体多巴胺浓度下降和黑质神经细胞减少。结论ＧＭ可减轻６－羟基多巴胺对黑质多巴胺能神经元的损伤。     

Chronic haloperidol and clozapine differentially affect dynorphin peptides and substance P in basal ganglia of the rat

The effect of chronic neuroleptic treatment, using haloperidol or clozapine, on immunoreactive dynorphin peptide and substance P levels in basal ganglia of rats was examined. The drugs were administered i.p. in daily doses for 10 days (haloperidol 1 mg/kg and clozapine 10 mg/kg). Dynorphin A, dynorphin B and substance P were measured in substantia nigra, striatum, globus pallidus and hypothalamus using specific radioimmunoassays. The most prominent effects were observed with with clozapine which increased levels of all measured peptides in substantia nigra. Haloperidol only affected nigral substance P levels which declined, while nigral dynorphin peptide levels remained unchanged. In striatum, haloperidol slightly reduced dynorphin peptides while substance P was unaffected. Clozapine increased striatal substance P but the dynorphin peptides were not affected. Minor changes in dynorphin peptides found in globus pallidus and hypothalamus were not statistically reliable. Substance P was not changed in these structures after either of the two drugs. High molecular weight fragments (greater than or equal to 5,000) from the dynorphin precursor, proenkephalin B, were measured in substantia nigra and striatum using trypsin digestion and subsequent analysis of generated Leu-enkephalin-Arg6. These high molecular weight fragments were found to be affected in the same manner as the dynorphin peptides. This study indicates that the two types of neuroleptic drugs have different modes of interaction on peptide systems in basal ganglia of rats. Dynorphin peptides and substance P were also differentially affected.