Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dopamine (DA) is a neurotransmitter intimately linked to cognitive and emotional processes, as well as to the pathophysiology and treatment of a variety of CNS disorders, such as schizophrenia, Parkinson's disease (PD) and drug abuse. For more than 25 years, the Dopamine Symposia have reviewed the progress in the fields of basic research and drug development at the highest scientific level. This year, the congress, which was attended by approximately 200 participants from academia and the pharmaceutical industry, was organized as a satellite symposium of the XIIIth IUPHAR Congress in Munich. There were 35 oral presentations and more than 100 posters, illustrating the current knowledge of physiological and pathophysiological functions of dopaminergic systems. Virtually all presentations focused on CNS effects of DA, neglecting its role in peripheral organs, clearly reflecting the focus of current interest. Since the cloning of five distinct DA receptor subtypes early this decade, the elucidation of their function and potential role as drug targets has been hampered by the lack of sufficiently selective tools. This gap is currently being filled by the advent of the first subtype-selective antagonists for DA D3 and D4 receptors, and by mice in which DA transporters or DA receptors are "knocked-out".
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PMID:Dopamine 98. 22-25 July 1998, Strasbourg, France. 1846 13

A higher prevalence and incidence of Parkinson disease (PD) is observed in men and beneficial motor effects of estrogens are observed in parkinsonian women. Lesion of the dopamine (DA) nigrostriatal pathway in animals with 1-methyl 4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) provides a model of PD and this is based on its use in humans as side-product of a drug abuse. Presently treatment of PD is mainly symptomatic. The MPTP mouse is used to study the neuroprotective roles of estrogenic drugs on the DA system. Estrogens, but not androgens, are active neuroprotectants as well as progesterone and dehydroepiandrosterone. An estrogen receptor agonist PPT and the selective estrogen receptor modulator raloxifene are also neuroprotective. Striatal DA neurons of estrogen receptor alpha knockout mice are more susceptible to MPTP toxicity than wild-type mice and neuroprotection by estradiol is associated with the activation of the PI3-K pathway involving Akt, GSK3beta, Bcl2 and BAD.
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PMID:Estrogen and SERM neuroprotection in animal models of Parkinson's disease. 1851 1

Pathological gambling (PG) has been identified in patients with Parkinson's disease (PD) treated with dopamine agonists suggesting that dysregulation of brain dopaminergic activity may contribute to the development of gambling problems. The current study was undertaken to further establish the prevalence of problem and PG in patients with PD, identify any clinical correlates, and determine if psychiatric or substance use co-morbidity contributes to the increased prevalence of problem and PG. A cross-sectional survey of 140 serially recruited moderate to severe PD patients was undertaken utilizing the Canadian Problem Gambling Index, Alcohol Use Disorders Identification Test, Drug Abuse Screening Test, Beck Depression Inventory, Beck Anxiety Inventory, and Mini-Mental State Exam augmented by chart review, completed over an 8 month period. The 12 month prevalence of problem and PG in PD was 9.3% compared to 1.6% in the general population within a comparably aged sample. The increased prevalence of problem and PG in the PD group was related to dopamine agonist use and younger age, but not co-morbidity. Most subjects with problem and PG reported their gambling increased after being diagnosed with PD and starting treatment. The results suggest that brain dopaminergic activity is involved in the underlying neurobiology of problem and PG.
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PMID:Prevalence of problem and pathological gambling in Parkinson's disease. 1856 Oct

Central serotonergic and dopaminergic systems play a critical role in the regulation of normal and abnormal behaviours. Moreover, recent evidence suggests that the dysfunction of dopamine (DA) and serotonin (5-hydroxytriptamine, 5-HT) neurotransmission might underlie the pathophysiology of neuropsychiatric disorders, including depression, schizophrenia, attention deficit hyperactivity disorders, drug abuse, Gilles de la Tourette's syndrome and Parkinson's disease.
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PMID:Serotonin-dopamine interaction: an overview. 1877 25

In this review, the functional interactions between serotonin (5-HT) and dopamine (DA) neuronal systems are discussed with the focus on microdialysis studies in the rodent brain (mainly rats). 5-HT by itself is involved both directly and indirectly via actions on complex neuronal circuitry, in the regulation of DA release through multiple 5-HT receptors, playing a critical role in the development of normal and abnormal behaviours. Recent evidence suggests that dysfunction of dopaminergic and serotoninergic neurotransmitter systems contributes to various disorders including depression, schizophrenia, Parkinson's disease and drug abuse. Here we summarize recent neurochemical works that have extensively explored the role of 5-HT receptors in the control of DA central systems in both basal and drug-induced conditions, using in vivo microdialytic techniques. Several 5-HT receptor subtypes, including the 5-HT(1A), 5-HT(1B), 5-HT(2A), 5-HT(3) and 5-HT(4) receptors, act to facilitate DA release, while the 5-HT(2C) receptor mediates an inhibitory effect of 5-HT on DA release. Taken together, neurochemical approaches using microdialysis can not only contribute to clarification of the physiological role of the serotonergic neuronal systems but may also be a powerful pharmacological approach for the development of therapeutic strategies to the treatment of depression, schizophrenia, Parkinson's disease and drug abuse.
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PMID:Serotonin control of central dopaminergic function: focus on in vivo microdialysis studies. 1877 26

Although levodopa remains the most effective drug for the symptomatic treatment of Parkinson's disease, chronic therapy with this pharmacological compound initiates a complex cascade of cellular and molecular downstream effects resulting in the development of abnormal involuntary movements. The precise mechanisms underlying the development of levodopa induced dyskinesia, however, are far from being completely elucidated. In the present review, we will describe changes in long-term synaptic excitability following dopamine (DA) denervation and long-term levodopa treatment leading to abnormal involuntary movements. In particular, we will address the role of both DA D1 receptors and NMDA glutamate receptors in the induction and maintenance of dyskinesia and abnormal synaptic plasticity. We will also describe the possible interaction between these two receptors in the pathophysiology of dyskinesia taking the advantage of the existing knowledge concerning the mechanisms underlying drug abuse. This latter pathophysiological condition, in fact, seems to share several biochemical transduction pathways with those implicated in levodopa-induced dyskinesia. Finally, we will briefly discuss the possible implication of A2A adenosine receptors in long-term motor complications of levodopa therapy and focus on the interaction between A2A and D2 receptors. Future studies are required to understand how the interaction between these various biochemical steps converge to produce a long-term change in neuronal excitability within the basal ganglia leading to abnormal involuntary movements following levodopa treatment in the DA-denervated state.
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PMID:Molecular mechanisms underlying levodopa-induced dyskinesia. 1878 74

The psychostimulant, methylphenidate (MPD), is commonly prescribed to treat attention-deficit hyperactivity disorder. MPD binds to the neuronal dopamine (DA) transporter, where it blocks the inward transport of DA. The present study expands upon these findings by examining the effects of in vivo MPD administration on the vesicular monoamine transporter-2 (VMAT-2) in membrane-associated vesicle and cytoplasmic vesicle subcellular fractions (i.e., those vesicles that do and do not co-fractionate with synaptosomal membranes after osmotic lysis, respectively) isolated from lysates of rat striatal synaptosomes. The results indicate that a single MPD administration redistributes VMAT-2 and associated vesicles within nerve terminals away from the synaptosomal membranes and into the cytoplasm, as assessed 1 hour after treatment. DA transport is also increased by MPD in both vesicle fractions (on account of vesicle trafficking in the cytoplasmic vesicles and to kinetic upregulation of the VMAT-2 in the membrane-associated vesicles). This, in turn, leads to an increase in the DA content of both vesicle fractions as well as an increase in the velocity and magnitude of K(+)-stimulated DA release from striatal suspensions. Taken together, these data show that the trafficking, DA sequestration function, DA content, and exocytotic DA release function of synaptic vesicles can all be pharmacologically manipulated by in vivo MPD treatment. These findings may provide important insights useful for understanding and treating disorders involving abnormal DA transmission including drug abuse, Parkinson's disease, and attention-deficit hyperactivity disorder.
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PMID:Methylphenidate-induced alterations in synaptic vesicle trafficking and activity. 1899 73

In rare instances, patients with Parkinson's disease (PD) may become addicted to their own medication or develop behavioral addictions such as pathological gambling. This is surprising because PD patients typically have a very low incidence of drug abuse and display a personality type that is the polar opposite of the addictive personality. These rare addictive syndromes, which appear to result from excessive dopaminergic medication use, illustrate the link between dopamine, personality, and addiction. We describe the clinical phenomena and attempt to relate them to current models of learning and addiction. We conclude that persistently elevated dopaminergic stimulation promotes the development and maintenance of addictive behaviors.
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PMID:Personality, addiction, dopamine: insights from Parkinson's disease. 1924 71

This review focuses on the behavioral pharmacology of endogenous cannabinoids (endocannabinoids) and indirect-acting cannabinoid agonists that elevate endocannabinoid tone by inhibiting the activity of metabolic enzymes. Similarities and differences between prototype cannabinoid agonists, endocannabinoids and inhibitors of endocannabinoid metabolism are discussed in the context of endocannabinoid pharmacokinetics in vivo. The distribution and function of cannabinoid and non-CB(1)/CB(2) receptors are also covered, with emphasis on their role in disorders characterized by dopamine dysfunction, such as drug abuse and Parkinson's disease. Finally, evidence is presented to suggest that FAAH inhibitors lack the abuse liability associated with CB(1) agonists, although they may modify the addictive properties of other drugs, such as alcohol.
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PMID:In vivo pharmacology of endocannabinoids and their metabolic inhibitors: therapeutic implications in Parkinson's disease and abuse liability. 1952 30

A variety of evidence suggests important commonalities in the neurochemical basis of reinforcement in pathological gambling (PG) and psychostimulant addiction. This article focuses on the parallel and specific roles that dopamine (DA) activation plays in these two disorders, beyond its generic role in reinforcement. A psychostimulant-mimetic model for PG is proposed based on evidence from the following domains: Acute subjective-behavioral effects of gambling and psychostimulants; Effects of anticipated rewards and uncertainty of reward delivery (key elements of gambling) on DA release; Relationship between DA release and positive arousal; Cross-priming of motivation for gambling by amphetamine; Effects of DA D2 antagonists on gambling and amphetamine reward; Effects of mixed D1-D2 antagonists on clinical symptoms of PG; Effects of DA D2 agonists on experimental measures of risk-taking, gambling, and induction of PG in patients with Parkinson's disease; Electrophysiological and cognitive disturbances associated with chronic exposure to gambling and psychostimulants, and the possible role of sensitization in these effects. Limitations of the model regarding the exclusive role of DA are discussed with particular reference to genetic risk, co-morbidity, and sub-types of PG. Suggestions for future research include isolating the roles of DA receptor subtypes in PG, and parallel within-subject assessment of DA manipulations on gambling and psychostimulant reinforcement in PG subjects and controls.
Curr Drug Abuse Rev 2009 Jan
PMID:Parallel roles for dopamine in pathological gambling and psychostimulant addiction. 1963 Jul 34


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