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)

Comparison of the properties of blood platelets and serotonergic synaptosomes suggests that the human platelet can serve as an appropriate model for the transport, metabolism, and release of serotonin (5-HT) by CNS serotonergic neurons. The study of blood 5-HT levels and platelet 5-HT pharmacodynamics in patients with a variety of psychiatric and neurologic disorders has generated interesting leads into possible abnormalities of CNS 5-HT neurons in these patients. This article reviews the experimental evidence, which uses the human platelet model to investigate neurotransmitter-related abnormalities in Down syndrome, mental retardation, infantile autism, hyperactivity syndromes (minimal brain dysfunction), schizophrenia, affective disorders, Duchenne muscular dystrophy, Parkinson disease, Huntington chorea, and migraine headaches.
Arch Gen Psychiatry 1977 May
PMID:The human platelet. A diagnostic and research tool for the study of biogenic amines in psychiatric and neurologic disorders. 14 Jun 32

Before and during a standardized course of trifluoperazine therapy, 18 schizophrenic patients underwent repeated examinations for extrapyramidal motor signs, clinical psychopathology, and urinary excretion of free and conjugated forms of dopamine and its metabolites. Patients excreting more free dopamine and metabolites, or showing less complete conjugation, before drug treatment, were much less likely than others to develop parkinsonian akinesia and rigidity during drug treatment. Neither catatonic rigidity nor akinesia before treatment was predictive of a parkinsonian response to trifluoperazine, but pretreatment tremor may have been. The severity of schizophrenic psychopathology was unrelated to dopamine excretion. This study of schizophrenic patients, and our previous research in Parkinson's disease, suggest that urinary dopamine excretion may reflect dopaminergic function of the extrapyramidal motor system in both conditions.
Arch Gen Psychiatry 1978 Jan
PMID:Dopamine excretion and vulnerability to drug-induced Parkinsonism. Schizophrenic patients. 61 44

In the cerebrospinal fluid of the patients with Parkinson's disease treated with L-DOPA, L-3-O-methyldopa was the major metabolite of administered L-DOPA. Using a dopaminergic cell model, clonal rat phenochromocytoma PC 12h cells, and by microdialysis of the rat striatum it was proved that L-3-O-methyldopa was taken up into monoamine neurons by transport system specific for aromatic L-amino acids and inhibited transport of L-DOPA and other amino acids competitively. L-3-O-Methyldopa depleted allosteric regulation of the biopterin cofactor on activity of tyrosine hydroxylase, the rate-limiting enzyme of catecholamine synthesis. Depletion of the allostery may perturb the buffer action of endogenous L-DOPA synthesis that stabilizes dopamine level in the brain. By these mechanisms L-3-O-methyldopa may reduce clinical effectiveness of administered L-DOPA and be involved in wearing-off phenomenon. L-DOPA inhibited the activity of tryptophan hydroxylase and thus serotonin synthesis, which may be related to psychiatric side-effects in the patients under L-DOPA therapy.
J Neural Transm Gen Sect 1992
PMID:The mechanism of perturbation in monoamine metabolism by L-dopa therapy: in vivo and in vitro studies. 136 50

Free radicals are reactive chemical species with an unpaired electron that are produced through a variety of physiologic and pathologic processes. Free radicals have been implicated in a variety of neuropsychiatric conditions, many of which are marked by the gradual development of psychopathologic symptoms and movement disorder. There is evidence that radical-induced damage may be important in Parkinson's disease, tardive dyskinesia, metal intoxication syndromes, and Down's syndrome, and possibly also in schizophrenia, Huntington's disease, and Alzheimer's disease. Although some of this evidence is highly speculative, it may offer an avenue for further understanding and treatment of these conditions.
Arch Gen Psychiatry 1991 Dec
PMID:Oxygen radicals and neuropsychiatric illness. Some speculations. 184 28

Positron emission tomography (PET) following intravenous administration of beta-[11C]-L-DOPA provides a method of assessing regional cerebral uptake and utilization of levodopa. Cerebral levodopa kinetics in the rhesus monkey were investigated after the inhibition of catechol-O-methyltransferase (COMT) with RO 40-7592, and after coadministration of the peripheral aromatic L-amino acid decarboxylase (AADC) inhibitors benserazide and carbidopa. Pretreatment with RO 40-7592 (10 mg/kg), benserazide (10 mg/kg) or carbidopa (3.5 mg/kg) did not change striatal k3, which mainly reflects the ability for the brain tissue to convert [11C]-L-DOPA to [11 C]-dopamine, although the brain's uptake of radioactivity increased substantially after pretreatment with the AADC inhibitors. When benserazide was coadministered with RO 40-7592 (10 mg/kg) a dose-dependent decrease in striatal k3 was measured with an apparent ED50 of 3 mg/kg. No such effect was indicated after pretreatment with the combination of RO 40-7592 (10 mg/kg) and carbidopa (3.5 mg/kg). The possible negative interactions of coadministration with COMT inhibitors and predominantly peripherally acting AADC inhibitors must be considered when used in the therapy of Parkinson's disease.
J Neural Transm Gen Sect 1991
PMID:Central action of benserazide after COMT inhibition demonstrated in vivo by PET. 186 35

In a general practice population of 57 000, 32 patients suffering from Parkinson's disease were identified from repeat prescription indexes and direct questioning of all members of the primary health care team. Of these patients 26 were receiving an L-dopa preparation and 10 an anticholinergic drug. The only newer drug found to be in use was bromocriptine and three patients were receiving this treatment.Of the 26 patients receiving an L-dopa preparation one received L-dopa alone, six L-dopa with benserazide (Madopar, Roche) and 19 L-dopa with carbidopa (Sinemet, Merck, Sharp and Dohme). The patients treated with Sinemet were receiving inadequate doses of carbidopa - three quarters received less than 75 mg per day which was in part a reflection of the low doses of L-dopa the patients received, the average dose being 468 mg per day. The L-dopa preparations were given in adequately spaced doses.The general practitioner made the diagnosis in 20 of the 32 cases and was in control of the drug therapy in 15 cases, however 25 cases were referred for specialist advice.
J R Coll Gen Pract 1985 Jun
PMID:Audit of the drug treatment of Parkinson's disease in general practice. 403 54

This paper documents the recent dramatic shift towards the delivery of psychiatric services in the general hospital setting and outlines the increasing number of special indications for electroconvulsive therapy (ECT). These include: delusional depression; depressions which are not responsive to antidepressants; affective illness in geriatric populations, depression, mania or schizophrenia in patients who cannot tolerate medication side effects, and drug-refractory Parkinson's disease. Such technological advances as nondominant unilateral placement of electrodes, brief pulse electrical stimulation, and simultaneous ictal monitoring of EEG and EKG have increased the safety while reducing the side effects of the procedure. In that comparative studies show ECT to have safety and efficacy superior to antidepressant agents in the treatment of severe depressive illness, the author encourages physicians to consider this treatment which is becoming increasingly available through our general hospital services.
Gen Hosp Psychiatry 1981 Dec
PMID:Electroconvulsive therapy in general hospital psychiatry: a focus on new indications and technologies. 731 23

Since the introduction of levodopa therapy for idiopathic Parkinson's disease over 20 years ago, there has been an awakening of research interest in this chronic neuro-degenerative disorder. This paper describes current understanding of the role of genetic and environmental factors in the aetiology of idiopathic Parkinson's disease and problems associated with both diagnosis and management. It briefly outlines both pharmacological and non-pharmacological options for treatment. Despite an increasing armoury of available treatments, the optimum management for this condition remains controversial.
Br J Gen Pract 1995 May
PMID:Idiopathic Parkinson's disease: epidemiology, diagnosis and management. 761 74

Some treatments used for Parkinson's disease attenuate locomotor depression in rats treated with reserpine and alpha-methyl-p-tyrosine. In the present study memantine (2.5, 5.0 mg/kg), amantadine (10, 20 mg/kg) (both uncompetitive NMDA antagonists), and L-deprenyl (1.0, 5.0 mg/kg; MAO-B inhibitor) were tested for possible synergistic interactions with the dopamine agonists: bromocriptine (2.5, 5.0 mg/kg) and L-dopa (50, 100 mg/kg, +benserazide, 100 mg/kg). At higher doses, memantine (10 mg/kg), amantadine (40 mg/kg), bromocriptine (5 and 10 mg/kg) and L-dopa (100, 200 mg/kg) but not L-deprenyl (up to 10 mg/kg) produced a pronounced increase in locomotor activity when given alone. The combination of memantine, amantadine and L-deprenyl with bromocriptine did not result in synergism of action and, at best, an additive effect was seen. On the other hand the combination of these agents with L-dopa produced a pronounced synergistic effect. Hence, the clinical observation that coadministration of L-dopa with either memantine or amantadine results in enhancement of their action is also reflected in an animal model of Parkinson's disease. Such a combination therapy should allow the use of lower doses of both drugs which may reduce the occurrence of side effects and may also be predicted to have additional benefits related to the neuroprotective properties of memantine, amantadine, and L-deprenyl.
J Neural Transm Gen Sect 1994
PMID:Memantine, amantadine, and L-deprenyl potentiate the action of L-dopa in monoamine-depleted rats. 771 Jul 39

Although the involvement of monoamine oxidase B (MAO-B) in physiological function is not yet well understood, its inhibitors have been shown to be quite useful in the treatment of various neuropsychiatric disorders. Platelet MAO-B activity has been found to be reduced in several psychiatric disorders, related to substance abuse and associated with different personalities. 1-Deprenyl (selegiline), an archetypical MAO-B inhibitor, alone does not seem to exert an antidepressive effect, however, it may become useful when administered in combination with amine neurotransmitter precursors. MAO-B inhibitors are useful adjunct drugs to 1-DOPA in the symptomatic treatment of Parkinson's disease. Interestingly, 1-deprenyl alone can slow down the progress of otherwise disabled syndromes of Parkinson's disease. It has been proposed that 1-deprenyl may play a role in neuroprotection and neurorescue. MAO-B inhibitors can selectively and dramatically increase the level of beta-phenylethylamine, which has been shown to potentiate dopamine and noradrenaline function in the central nervous system. Several new types of highly selective, reversible and irreversible MAO-B inhibitors have recently been developed. The mechanism(s) of neuroprotective and rescue actions of 1-deprenyl and other MAO-B inhibitors will help to shed some light on our understanding of the neurodegenerative process.
Gen Pharmacol 1994 Dec
PMID:Pharmacological and clinical implications of MAO-B inhibitors. 772 Oct 26


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