Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0233565 (bradykinesia)
2,352 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to cats results in a parkinsonian syndrome characterized by rigidity, akinesia, bradykinesia, decreased response to external sensory stimuli and depletion of nigrostriatal dopamine. Cats spontaneously recover gross sensorimotor functions despite little recovery of the dopaminergic innervation of the striatum. In contrast, GM1 ganglioside administration accelerates gross behavioral recovery and causes an increased dopaminergic innervation of the striatum. This study examined whether these two recovery conditions are characterized by different degrees of functional recovery. Cats were trained to perform a sensorimotor reaching task prior to MPTP exposure and were then re-tested on the task 6 weeks later after spontaneously recovering gross motor functioning or after 6 weeks of GM1 treatment. Gross motor recovery was similar in both groups. However, the spontaneously recovered cats had significant difficulty in performing the task while GM1-treated cats performed normally. GM1-treated cats also had significant increases in striatal [3H]mazindol binding compared to spontaneously recovered cats. These results suggest that while gross motor functions may improve to a similar extent with spontaneous and GM1-induced recovery from experimental parkinsonism, complex sensorimotor behavior recovers to different extents under the different recovery conditions. More complete behavioral recovery may depend upon at least a partial recovery of striatal dopaminergic terminals rather than neurochemical compensation.
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PMID:Differential recovery of sensorimotor function in GM1 ganglioside-treated vs. spontaneously recovered MPTP-treated cats: partial striatal dopaminergic reinnervation vs. neurochemical compensation. 982 74

Glial cell line-derived neurotrophic factor (GDNF) has previously reduced motor deficits and preserved nigral dopamine neurones in rhesus monkeys with a unilateral MPTP-induced lesion of substantia nigra. We now report on the ability of GDNF to reverse motor deficits induced by parenteral administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to common marmosets resulting in bilateral degeneration of the nigrostriatal pathway. Prior to GDNF administration, all MPTP-treated animals showed akinesia or bradykinesia, rigidity, postural instability and tremor. Intraventricular injection of GDNF (10, 100 or 500 microg) at 9 and 13 weeks post MPTP treatment resulted in a concentration dependent improvement in locomotor activity and motor disability which became significant after administration of 100 and 500 microg of GDNF. The most prominent improvements were in alertness, checking movements, and posture. It is concluded that intraventricular GDNF administration improves bilateral Parkinsonian motor disability following MPTP treatment and this may reflect an action of GDNF on remaining nigral dopaminergic neurones.
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PMID:Glial cell line-derived neurotrophic factor concentration dependently improves disability and motor activity in MPTP-treated common marmosets. 1116 35

Inactivation of neurones in the subthalamic nucleus (STN) of the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine treated monkey model of Parkinson's disease has been shown to relieve parkinsonian motor symptoms. In patients with Parkinson's disease, neurones in the STN display hyperactive firing rates and rhythmic discharge activity such as tremor-related oscillations (3-8 Hz) and synchronous high-frequency oscillations (15-30 Hz). In this study, microinjections of lidocaine (n = 4) and muscimol, a GABA(A) receptor agonist (n = 2), were performed in the STN of six patients with Parkinson's disease to determine whether the focal suppression of STN neuronal activity can lead to an improvement in tremor, bradykinesia and rigidity. We also report the first use of microelectrode recording of the effects of microinjections on neuronal activity in the human brain (n = 2). Microinjections of 10-23 microl of lidocaine produced striking improvements in bradykinesia, limb tremor and rigidity in three out of three patients. These improvements were correlated with good therapeutic effects of subsequent STN deep brain stimulation performed in the same microelectrode trajectories as these injections. The most dramatic observation following lidocaine injections was the appearance of dyskinetic limb movements. In one patient, simultaneous microelectrode recording during an injection of 3.5 microl of lidocaine demonstrated a suppression of neuronal activity at distances of < 0.9 mm from the injection site, but no suppression was observed at > or = 1.2 mm from the injection site. Microinjections of 5-10 microl of muscimol in a region with tremor-related activity resulted in suppression of limb tremor in two out of two patients. Interestingly, in one of these patients, 4 Hz oscillatory activity was diminished in a neurone recorded 1.3 mm from the injection site, but there was no reduction in the mean firing rate or 20 Hz oscillatory activity. These results demonstrate that inactivation of neuronal activity in the STN of patients with Parkinson's disease improves motor symptoms. These findings also suggest that a focal block of the STN might alter the oscillatory activity of neurones located beyond the inhibited region.
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PMID:Lidocaine and muscimol microinjections in subthalamic nucleus reverse Parkinsonian symptoms. 1157 Dec 26

Parkinson's disease (PD) is the second most common neurodegenerative disorder affecting 1 to 3% of individuals over the age of 65 years. While effective therapy exists for treating the bradykinesia, rigidity and tremor associated with the disease, the cause is unknown. There is no treatment available to prevent or slow the progressive neuronal loss in the substantia nigra and associated decreased levels of dopamine in the striatum that underlie the cardinal features of the disease. Both retrospective and prospective epidemiological studies have consistently demonstrated an inverse association between cigarette smoking and PD, leading to theories that smoking in general and nicotine in particular might be neuroprotective. Nicotine has been shown in animals to stimulate the release of dopamine in the striatum, and to preserve nigral neurons and striatal dopamine levels in laboratory animals with lesioned nigrostriatal pathways. Coffee and caffeine consumption have also been shown in epidemiological studies to be inversely related to PD risk. Caffeine is an adenosine A(2A) receptor antagonist that enhances locomotor activity in animal models of parkinsonism. Theophylline, a related compound that has A(2A) receptor blocking properties, has been shown in one small trial to improve motor function in patients with PD. Recently, potent and highly selective A(2A) receptor antagonists have been developed that have demonstrated improvement in motor function in animal models of parkinsonism. Exciting findings are emerging that demonstrate attenuation of dopaminergic neurotoxicity with caffeine and other adenosine receptor antagonists in mice given the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), suggesting that these compounds may be neuroprotective. Evidence for the neuroprotective potential of nicotine and caffeine is compelling, but further work is needed before testing these and related compounds in clinical trials for both individuals at high risk of developing PD and those with early, untreated disease.
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PMID:Current evidence for neuroprotective effects of nicotine and caffeine against Parkinson's disease. 1177 20

The discovery of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) leads to the hypothesis that Parkinson's disease (PD) is maybe initiated or precipitated by environmental or endogenous toxins by the mechanism similar to that of MPTP in genetically-predisposed individuals. Endogenous analogs of MPTP, such as beta-carbolines (betaCs) and tetrahydroisoquinolines, have been proposed as possible causative candidates causing PD and are bioactivated into potential neurotoxins by N-methylation enzyme(s). These N-methylated betaCs and tetrahydroisoquinoline have been higher cerebrospinal levels in parkinsonian patients than age-matched controls. Thus, there is a hypotheses to influence the pathogenesis of PD, that is, the excess enzyme activity to activate neurotoxins, such as N-methyltransferase, might be higher in PDs. Indeed, simple betaCs, via N-methylation steps, induced bradykinesia with the decreased dopamine contents in the striatum and midbrain in C57/BL mice. In younger (65 years old) PD patients, the excretion amount of N(1)-methyl-nicotinamaide was significantly higher than that in younger controls. The protein amount of nicotinamide N-methyltransferase (NNMT) was also significantly higher in younger PD patients than that in younger controls. These findings described here would indicate that the excess N-methylation ability for azaheterocyclic amines, such as betaCs, before the onset had been implicated in PD pathogenesis. On the other hand, the contribution of aberrant cytochrome P450 or aldehyde oxidase activity acting on the pyridine ring, that could act as detoxification routes of endogenous neurotoxins, would be small in the etiology of PD.
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PMID:N-methylation underlying Parkinson's disease. 1220 Jan 90

The levels of mRNA encoding the two isoforms of glutamic acid decarboxylase (GAD(65) and GAD(67)) were measured throughout the pallidal complex in normal and acutely (i.e., 1 month duration) and chronically (i.e., 5 years duration) parkinsonian 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP) -treated monkeys as well as in monkeys exposed to MPTP but asymptomatic for parkinsonism. GAD(65) mRNA labeling was modestly increased in the mid/caudal internal globus pallidus (GPi) but not in the external globus pallidus (GPe) in parkinsonian monkeys, compared with normal and asymptomatic monkeys. GAD(67) mRNA expression was highly increased in the mid/caudal GPi, and modestly increased in the GPe in parkinsonian monkeys compared with normal and asymptomatic animals. Infusion of GAD(67) antisense oligodeoxynucleotides bilaterally into the GPi resulted in a transient reversal of akinesia and bradykinesia that was not produced by infusion of missense oligodeoxynucleotides. These data emphasize the role of GAD enzyme (particularly GAD(67)) and GABA in the GPi for the expression of parkinsonian motor signs and suggest that selective manipulation of GABAergic neurotransmission in the GPi may have therapeutic potential for treating parkinsonism.
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PMID:Experimental parkinsonism is associated with increased pallidal GAD gene expression and is reversed by site-directed antisense gene therapy. 1251 98

We administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to adult, male cats to model Parkinson's disease (PD), and utilized proton magnetic resonance imaging (MRI) and spectroscopy (MRS) at a field strength of 1.5 T to identify metabolic degenerative changes in the striatum in vivo. Neurologic status and somatosensory-evoked potentials in vivo, as well as postmortem striatal histopathological and immunohistochemical parameters, were examined. Nine cats were equally divided into three groups and treated daily for 10 days as follows: saline, MPTP, and pargyline (a monoamine oxidase inhibitor) plus MPTP. The MPTP-treated cats displayed bradykinesia, head tremor, and reduced oculovestibular reflex activity. MRI showed a diffuse increase of the T2-weighted signal in the striatum of two MPTP-treated cats. Analysis of the MRS spectra indicated significantly lower N-acetylaspartate/creatine (CR) and glutamine-glutamate complex/CR ratios than the control baseline. Two MPTP-treated cats had low choline-containing compounds/CR ratio, whereas a lactate peak was present in all MPTP-treated cats. In the striatum of the MPTP-treated cats, there was a significant decline of tyrosine hydroxylase immunoreactivity and histological evidence for a diffuse cytotoxic reaction. Pretreatment with pargyline attenuated the MPTP-induced clinical signs, MRI and MRS changes, and the histopathological and immunoreactivity alterations. We conclude that proton MRI/MRS is a sensitive, noninvasive measure of neural toxicity and biochemical alteration of the striatum in a feline model of PD.
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PMID:Proton magnetic resonance imaging and spectroscopy identify metabolic changes in the striatum in the MPTP feline model of parkinsonism. 1261 22

Parkinson's disease is the second most common neurodegenerative disorder after Alzheimer's disease. This disease is mainly characterized by tremor, bradykinesia, rigidity and postural instability that results primarily from a loss of dopaminergic neurons of the nigrostriatal pathway. MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) is well known to damage the nigrostriatal dopaminergic pathway, as seen in Parkinson's disease. Recent evidence shows that glial-related response plays a key role in the MPTP neurotoxic process, and the blockade of glial activation may be a new therapeutic approach to treating Parkinson's disease. In view of these new insights, this article suggests that the overexpression of S100beta protein secreted by glial cells may be an exacerbating factor in the neurodegeneration of dopaminergic cells in MPTP-treated animals. (c) 2002 Prous Science. All rights reserved.
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PMID:Glial Cells as a Target for the Development of New Therapies for Treating Parkinson's Disease. 1267 99

Diethyldithiocarbamate (DDC) is known to potentiate the neurotoxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The aims of the present study were to provide biochemical, pathological and behavioral evidence for the degeneration of dopamine (DA) neurons in C57BL/6 strain mice treated simultaneously with DDC and MPTP, and to evaluate the effects of monoamine oxidase (MAO) inhibitors on DDC-enhanced MPTP toxicity. DDC (400 mg/kg)+ MPTP (30 mg/kg) treatment decreased significantly the levels of striatal DA and its metabolites and induced bradykinesia. In mice treated with DDC+MPTP, degenerative areas were found in striatum, substantia nigra and tuberculum olfactorium by assessment of the binding of [125I]RTI-121, a DA transporter ligand. Pretreatment with a MAO-B inhibitor selegiline prior to the administration of DDC and MPTP completely inhibited the decrease in the levels of DA and its metabolites, bradykinesia and degeneration of dopaminergic nerve terminals. In contrast, the protective action of clorgyline was not clearly observed in this model system.
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PMID:Effects of monoamine oxidase inhibitors on the diethyldithiocarbamate-induced enhancement of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity in C57BL/6 mice. 1289 42

Diethyldithiocarbamate (DDC) enhances the neurotoxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We studied the time course of dopaminergic parameters and motor function of MPTP+DDC-lesioned C57BL/6 mice, a model of Parkinson's disease. MPTP+DDC-lesioned mice showed a decrease in dopamine (DA) and its metabolites contents in their striata 1, 3 and 6 weeks after MPTP+DDC-treatment, compared with those of each control group. The partial and significant recoveries in DA, 3,4-dihydroxyphenylacetic acid, and homovanillic acid contents were also observed after 6 weeks, compared with those at 1 week after treatment. In addition, bradykinesia due to DA depletion was observed in mice 1 week after MPTP+DDC-treatment, but it was not significant 3 weeks after the treatment. l-DOPA alone and a co-administration of l-DOPA and a monoamine oxidase-B inhibitor selegiline improved bradykinesia of this model, also suggesting that bradykinesia observed in the model was mediated to dopaminergic deficiency. On the other hand, the serotonin content increased slightly but significantly after 3 or 6 weeks, suggesting compensatory activation of the serotonergic system against DA depletion. Thus, the partial recovery of dopaminergic parameters, the recovery of motor function and the compensatory activation of the serotonergic system were observed in this model 3-6 weeks after MPTP+DDC treatment.
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PMID:Recovery of motor function and dopaminergic parameters in a mouse model of Parkinson's disease induced by co-administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and diethyldithiocarbamate. 1289 43


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