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)

Parkinson's disease is challenging to diagnose and treat. Patients are subject to wide fluctuations of motor status as well as an array of nonmotor complications that may be as debilitating as their motor counterparts, or even more debilitating. Levodopa remains the most effective agent for relief of motor symptoms, but long-term levodopa use is associated with development of motor complications, including severe dyskinesias. For this reason, selegiline or a dopamine agonist may be preferred as initial therapy. Carbidopa/levodopa (with or without a COMT inhibitor) can be added within 5 years or as required for relief of motor symptoms. When medical therapy can no longer provide adequate symptom control, surgical intervention needs to be considered.
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PMID:A comprehensive approach to Parkinson's disease. How to manage fluctuating motor and nonmotor symptoms. 1691 48

The aim of the present study was to evaluate the contribution of MAOB, COMT, NAT2 and CYP2D6 gene polymorphisms to early onset Parkinson's disease (PD). The study enrolled 134 patients with Parkinson's disease (early onset-EOPD--67 patients, and late onset--LOPD--patients), and 66 healthy individuals. Polymerane chain reaction restriction fragment length polymorphism (PCR-RFLP) methods were used for genotyping. Univariate analysis revealed a significant two-fold higher EOPD risk among carriers of MAOB allele A or AA genotype. Multivariate analysis revealed that MAOB allele A was an independent factor predisposing to EOPD. It was shown that neither NAT2, CYP2D6 nor COMT genotype was associated with PD.
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PMID:Polymorphisms of catechol-0-methyltransferase (COMT), monoamine oxidase B (MAOB), N-acetyltransferase 2 (NAT2) and cytochrome P450 2D6 (CYP2D6) gene in patients with early onset of Parkinson's disease. 1727 Apr 84

Serum folate and vitamin B12 levels were measured in 67 consecutive Parkinson's disease patients treated either with levodopa + dopa decarboxylase inhibitor (DDC-i) plus catechol-O-methyltransferase inhibitors (COMT-i) or only with levodopa + DDC-i. The data were compared to 67 age-matched controls. Our findings show that levodopa-treated Parkinson's disease patients have low folate (p < 0.0007) and vitamin B12 levels (p < 0.0003). They also demonstrate that the addition of a COMT-i to levodopa + DDC-i treatment causes lower serum vitamin B12 (p < 0.03) and folate levels (p < 0.005) than levodopa + DDC-i treatment alone. We suggest supplementary treatment with vitamin B12 and folic acid in these situations.
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PMID:The influence of levodopa and the COMT inhibitor on serum vitamin B12 and folate levels in Parkinson's disease patients. 1756 22

Activated microglial cells are found in the substantia nigra and the striatum of Parkinson's disease patients. These cells have been shown to express catechol-O-methyltransferase activity which may increase during pathological conditions. Lipopolysaccharides are potent activators of microglial cells. After paranigral lipopolysaccharide infusion to rats we observed intense microglial activation around the lesion area followed by a delayed injury in nigrostriatal pathway in 2 weeks. Simultaneously, catechol-O-methyltransferase activity in the substantia nigra was gradually increased up to 213%. In the Western blot the amount of soluble COMT and membrane bound COMT proteins were increased by 255% and 86%, respectively. Increased catechol-O-methyltransferase immunoreactivity was located primarily into the activated microglial cells in the lesion area. Interestingly, catechol-O-methyltransferase and OX-42 stained also intensively microglia/macrophage-like cells which surrounded the adjacent blood vessels. Inhibition of catechol-O-methyltransferase activity by tolcapone or entacapone did not increase lipopolysaccharide-induced neurotoxicity. We conclude that catechol-O-methyltransferase activity and protein expression were increased in the substantia nigra after inflammation induced by lipopolysaccharides. These changes in glial and perivascular catechol-O-methyltransferase activity may have clinical relevance for Parkinson's disease drug treatment due to increased metabolism of levodopa in the brain.
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PMID:Increased catechol-O-methyltransferase activity and protein expression in OX-42-positive cells in the substantia nigra after lipopolysaccharide microinfusion. 1757 59

A satisfactory motor control can be achieved for many years in Parkinson's disease (PD). Clinical management is more complex when disease progresses and occurrence of motor fluctuations and dyskinesias negatively impacts on patients' quality of life. Mobility depends increasingly on levodopa peripheral bioavailability. Medical strategies consist of raising the number of levodopa administrations and the association with COMT inhibitors, entacapone or the more potent tolcapone. MAO-B inhibitors rasagiline or selegiline can be also added. When these options fail, achievement of motor control requires more complex therapeutic strategies: continuous infusion of dopaminergic drugs or neuromodulation with deep brain stimulation (DBS). Apomorphine is a dopamine agonist that can provide motor benefit similar to dopamine, but its use is limited by compliance, local skin reactions at the site of injection and risk of psychiatric adverse events, particularly when round-the-clock administration is used. DBS of the subthalamic nucleus is very effective but feasible only for a small number of patients mostly because of age constraints. Continuous duodenal infusion of levodopa/carbidopa allows replacement of oral therapy resulting in marked improvement of quality of life and activities of daily living. Interestingly, this procedure produces a satisfactory therapeutic response that is paralleled by a reduction in dyskinesia severity.
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PMID:New strategies in motor parkinsonism. 1826 81

The saga of harmful administration of levodopa (LD) in the treatment of Parkinson's disease (PD) resulted from outcomes of animal trials and cell culture studies. They were initiated after the clinical observation of onset of motor complications related to the short plasma half-life of the drug in PD patients. This discussion only partially considered a further aspect, which is associated with the long-term administration of LD. Chronic LD intake increases homocysteine plasma levels. This may support progression of the disease due to concomitant onset of neuropsychiatric symptoms and comorbidities (i.e., vascular disease). In the periphery, therapeutic approaches for this LD-mediated homocysteine increase are vitamin supplementation (i.e., folic acid or application of LD with an inhibitor of catechol-O-methyltransferase [COMT]). In the brain, a blood-brain trespassing precursor of folic acid or a centrally acting COMT inhibitor may represent hypothetical therapeutic approaches. This COMT inhibitor should be applied together with an oxidative stress reducing monoamine oxidase-B inhibitor, in order to force central dopamine metabolism further down via the methylation path. However, this may turn out to be a double-edged sword, since the inhibition of O-methylation with the COMT inhibitor may hypothetically contribute to increased N-methylation. Thus, endogenous tetrahydroisoquinolines may be transformed to neurotoxic N-methylated tetrahydroisoquinolines. These neurotoxic compounds were observed in cerebrospinal fluid and plasma of long-term LD-treated PD patients. They have a structure similar to 1-methyl 4-phenyl 1,2,3,6-tetrahydropyridine or its ion 1-methyl-4-phenylpyridinium, both of which are known to induce PD-like motor symptoms.
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PMID:Role of homocysteine in the treatment of Parkinson's disease. 1850 60

The authors present the current opinion on the significance of molecular biology in individualized therapy. Pharmacogenetics is a new branch of clinical pharmacology dealing with the influence of genetic factors on drugs with special focus on interpersonal differences to drug response. The article includes basic rules of pharmacogenetics as well as its use in clinical practice. Individualized treatment of Parkinson's disease is not widely known although interpersonal differences to drug response is clearly stated. There is some evidence that varied efficacy of treatment and risk of motor and mental complications can be of genetic origin. Some results concerning the relationship between genetic polymorphism of COMT, DRD2, DAT, CCK, MTHFR and successful and safe treatment of Parkinson's disease are presented.
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PMID:[Pharmacogenetics in Parkinson's disease treatment]. 1851 70

Levodopa is the most effective treatment in Parkinson's disease and the association with COMT inhibitors widens its plasma bioavailability and effectiveness. Tolcapone is a potent COMT inhibitor whose utilization in PD is limited due to safety concerns on liver toxicity. However, recent data indicate that if liver function is actively monitored, tolerability is no worse than other currently available therapies. By contrast, administration of tolcapone is associated with significant clinical improvement and benefit involves also non-motor features. In this review we discuss the rationale for the use of tolcapone in association with levodopa and other treatments in PD, and we provide an indirect comparison of current strategies to reduce "off" time. We propose that future guidelines include a trial with tolcapone in all PD patients who continue to complain about motor fluctuations despite treatment with entacapone and/or MAO-B inhibitors. Moreover, we suggest that tolcapone should be considered before surgical or infusional strategies are applied.
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PMID:COMT inhibition with tolcapone in the treatment algorithm of patients with Parkinson's disease (PD): relevance for motor and non-motor features. 1872 67

We investigated whether the val(158)met functional polymorphism of catechol-o-methyltransferase influenced age-related changes in grey matter density and volume, both in healthy individuals (n=80, ages 18-79) and those with Parkinson's disease (n=50). Global grey matter volumes and voxelwise estimates of grey matter volume and density were determined from structural magnetic resonance images at 3T. Male and female ValVal homozygotes (low prefrontal cortical dopamine) had more grey matter in early adulthood, but this difference disappeared with increasing age. The insula and ventral prefrontal cortex had higher grey matter volume in younger, but not older, ValVal homozygotes. Conversely, the dominant premotor cortex revealed genotypic differences in grey matter density in later life. There were no global or local interactions between Parkinson's disease and COMT val(158)met genotype on morphometry. Since the val(158)met polymorphism is associated with differences in cortical dopamine metabolism, our data suggest a role for dopamine in cortical development followed by differential vulnerability to cortical atrophy across the adult life span.
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PMID:The val158met COMT polymorphism's effect on atrophy in healthy aging and Parkinson's disease. 1875 26

Rasagiline, a selective COMT inhibitor, and rotigotine, a transdermal dopamine (D2) agonist, are two new agents that have been approved in the U.S. and Europe for the treatment of Parkinson's disease. Rasagiline is approved in the U.S. for both monotherapy and as an adjunct to levodopa. Its role in preventing disease progression has yet to be proven, but a large-scale study (ADAGIO) is under way. Rotigotine is approved for early-stage disease in Europe and the U.S. but is only approved in Europe for late-stage disease. It has recently been recalled due to the formation of insoluble crystals that interfere with absorption and may reduce its efficacy. Measures are being taken by the manufacturer to solve this problem. Istradefylline, and adenosine receptor antagonist, showed early promise but efficacy has not been demonstrated consistently, possibly due to higher than expected placebo effect. This has resulted in a nonapprovable letter from the FDA. With regard to perampanel, additional studies are needed to demonstrate safety and efficacy. Sanifamide and pardoprunox are agents that target multiple receptors that may modulate dyskinesia and other nonmotor symptoms in addition to motor symptoms, but phase III data are not yet available. Lusuride is an older dopamine agonist that has been reformulated as a transdermal patch and as a subcutaneous injection and may offer advantages in refractory patients with motor fluctuations. Sphermaine is a novel cell therapy designed to provide a localized source of levodopa directly to the brain. Gene therapies including AAV-GAD, AAV-AADC and AAV2-neurturin are in early stages of development in patients with advanced-stage disease but early safety data are promising.
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PMID:New frontiers in the pharmacological management of Parkinson's disease. 1880 3


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