Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sodium valproate, nipecotic acid, diaminobutyric acid (DABA) and beta-alanine are drugs which enhance transmission mediated by gamma-aminobutyric acid (GABA) by a variety of mechanisms. They were used to study the role of GABA in the high pressure neurological syndrome (HPNS) in the rat. Sodium valproate, nipecotic acid and DABA reduced the increase in slow waves seen in the electroencephalogram (EEG) of control rats at pressures above 10-20 ATA; however, only sodium valproate had a beneficial effect on the behavioural signs of the high pressure neurological syndrome (tremor, myoclonus and convulsions). Sodium valproate is also thought to decrease neurotransmission produced by excitatory amino acids; thus, these results suggest that GABA is not one of the major neurotransmitters involved in all aspects of the high pressure neurological syndrome and that changes in excitatory neurotransmission may affect the behavioural signs.
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PMID:Gamma-aminobutyric acid and the high pressure neurological syndrome. 309 Apr 69

Ten patients with clinically definite multiple sclerosis (MS) and action tremor were treated with isoniazid (INH) in a double-blind single crossover trial. The daily dose of INH administered during the 4-week treatment phase of the trial was determined by acetylator phenotype with slow acetylators receiving 12 mg/kg per day and rapid acetylators 20 mg/kg per day. Six of eight patients who completed the trial showed clinical improvement in the postural (alternating) tremor while on INH but the degree was minimal in all cases. Results of tremograms indicated that improvement also occurred in the intentional (synchronous) component of three patients while on INH, but this did not achieve statistical significance. Cerebrospinal fluid (CSF) levels of gamma-aminobutyric acid (GABA) homocarnosine and ornithine were markedly elevated with INH therapy (providing evidence for substantial inhibition of GABA aminotransferase activity and increase in GABA in the CNS), but no correlation was found between the degree of GABA elevation in the CSF and the clinical response. Side effects were minimal and well tolerated. Although INH appears to have a limited therapeutic role, a trial is warranted in MS patients with postural tremor.
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PMID:A controlled trial of isoniazid therapy for action tremor in multiple sclerosis. 354 5

Progabide, a gamma-aminobutyric acid agonist, was given to ten patients with essential tremor in a double-blind, placebo-controlled crossover study. The effect of progabide did not differ from that of placebo. Alterations in gamma-aminobutyric acid neurotransmission do not appear to be involved in the pathogenesis of essential tremor.
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PMID:Pharmacologic probe with progabide of GABA mechanisms in essential tremor. 361 8

Exposure to high hydrostatic pressure produces neurological changes referred to as the high-pressure nervous syndrome (HPNS). Manifestations of HPNS include tremor, EEG changes, and convulsions. These symptoms suggest an alteration in synaptic transmission, particularly with inhibitory neural pathways. Because spinal cord transmission has been implicated in HPNS, this study investigated inhibitory neurotransmitter function in the cord at high pressure. Guinea pig spinal cord synaptosome preparations were used to study the effect of compression to 67.7 atmospheres absolute on [3H]glycine and [3H]gamma-aminobutyric acid ([3H]GABA) release. Pressure was found to exert a significant suppressive effect on the depolarization-induced calcium-dependent release of glycine and GABA by these spinal cord presynaptic nerve terminals. This study suggests that decreased tonic inhibitory regulation at the level of the spinal cord contributes to the hyperexcitability observed in animals with compression to high pressure.
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PMID:Effect of pressure on the release of radioactive glycine and gamma-aminobutyric acid from spinal cord synaptosomes. 366 41

Regional amino acid concentrations were measured in rat brain fixed by microwave irradiation at three levels of elevated atmospheric pressure corresponding to different phases of the high-pressure neurological syndrome [20 atmospheres absolute (ATA), no clinical signs; 60 ATA, tremor; 85 ATA, severe tremor and myoclonic jerks]. No changes in amino acid content occurred at 20 or 60 ATA. At 85 ATA glutamine content increased in hippocampus, striatum, cerebellum, and substantia nigra, and gamma-aminobutyric acid content increased in hippocampus. It is suggested that enhanced glutamate release in various subcortical structures contributes to the myoclonic activity observed at 85 ATA.
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PMID:Regional amino acid concentration in the brains of rats exposed to high pressures. 371 8

It was observed in experiments on mice that the central action of phenibut (beta-phenyl-gamma-aminobutyric acid) diminished after destruction of brain dopaminergic neurons by 6-hydroxydopamine and after pretreatment with the dopamine receptor blocker haloperidol which suggests the dopaminergic component in the action of phenibut. In 13 of 16 patients receiving long-term treatment with antiparkinsonic drugs, addition of phenibut (0.25 g thrice daily for 10 days) resulted in marked clinical improvement with a significant increase of motor activity, as well as diminution of both rigidity and tremor. Follow-up showed a significant lowering of muscle tone of rigid muscles, augmentation of their strength and amplitude of movements. In 8 patients receiving phenibut without antiparkinsonic drugs the results were negligible.
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PMID:[Phenibut potentiation of the therapeutic action of antiparkinson agents]. 377 87

High hydrostatic pressure has been shown to produce neurological changes in humans which manifest, in part, as tremor, myoclonic jerks, electroencephalographic changes, and convulsions. This clinical pattern has been termed high-pressure nervous syndrome (HPNS). These symptoms may represent an alteration in synaptic transmission in the central nervous system with the inhibitory neural pathways being affected in particular. Since gamma-aminobutyric acid (GABA) transmission has been implicated in other seizure disorders, it was of interest to study GABAergic function at high pressure. Isolated synaptosomes were used to follow GABA release at 67.7 ATA of pressure. The major observation was a 33% depression in total [3H]GABA efflux from depolarized cerebrocortical synaptosomes at 67.7 ATA. The Ca2+-dependent component of release was found to be completely blocked during the 1st min of [3H]GABA efflux with a slow rise over the subsequent 3 min. These findings lead us to conclude that high pressure interferes with the intraterminal cascade for Ca2+-dependent release of GABA.
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PMID:Effect of pressure on [3H]GABA release by synaptosomes isolated from cerebral cortex. 380 14

Bicuculline methiodide (0.5-3 nmol) and picrotoxin (0.5-4 nmol) were injected uni- or bilaterally into the rat amygdala and the resulting behavioural, electroencephalographic and morphological alterations were studied. In rats treated unilaterally with lowest doses of either bicuculline or picrotoxin (0.5 and 1 nmol) increase in the locomotor activity, occasional myoclonus of the hindlimbs and wet dog shakes were observed. At doses of 2-3 nmol, both gamma-aminobutyrate antagonists produced a sequence of repetitively occurring behavioural alterations including limbic gustatory automatisms, tremor and myoclonus of the forelimbs, head nodding and rearing, that developed over 15-30 min and built up progressively into the recurrent motor limbic seizures lasting for 1-6 h. In animals injected bilaterally with either bicuculline (0.5-3 nmol) or picrotoxin (0.5-3 nmol) motor limbic seizures rapidly developed into the status epilepticus lasting for several hours. Bicuculline and picrotoxin produced both ictal and interictal epileptiform activity in the electroencephalogram. A spectrum of electroencephalographic changes consisted of high voltage fast activity, slow and fast voltage spiking, paraoxysmal bursts and periods of postictal depression. The earliest electrographic alterations appeared in the amygdala and then rapidly spread to cortical areas. Electrographic seizures started 1-10 min after unilateral injections of large doses of bicuculline and pictrotoxin (2-4 nmol). Ictal periods lasted for 1-2 min, recurred every 5-10 min and were followed by periods of depression of the electrographic activity. Bilateral injections of large doses of both gamma-aminobutyrate antagonists (2-3 nmol) resulted in the status epilepticus. Morphological examination of frontal forebrain sections with light microscopy revealed a widespread damage to the amygdala, olfactory cortex, substantia nigra, thalamus, hippocampus and neocortex. Pretreatment of animals with diazepam prevented the build-up of convulsive activity and brain damage produced by bicuculline or picrotoxin. Muscimol retarded the appearance and shortened the duration of convulsive activity, but did not alter the sequence and intensity of seizures. The results indicate that gamma-aminobutyrate antagonists, bicuculline and picrotoxin when directly applied to the amygdala can elicit in rats motor limbic seizures, epileptic changes in the electroencephalogram indicative of repetitive limbic seizures, and status epilepticus accompanied by seizure-related brain damage.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Injections of picrotoxin and bicuculline into the amygdaloid complex of the rat: an electroencephalographic, behavioural and morphological analysis. 397 84

Fumitremorgin A (FTA), a neurotropic mycotoxin induced dose-dependent abnormal behaviors, including tremor, clonic convulsion, kangaroo posture and tonic extensor convulsion in the mouse. FTA-induced tonic extensor convulsion was markedly suppressed by anticonvulsant, e.g. phenobarbital, phenytoin. Phenobarbital, trimethadione, valproic acid and mephenesin decreased the occurrence of abnormal behaviors induced by FTA. Although pentylenetetrazol-induced tonic extensor convulsion was not affected by antipsychotic drugs (dopaminergic drugs) except chlorpromazine, FTA-induced abnormal behaviors were inhibited by antipsychotic drugs, e.g. chlorpromazine, haloperidol. Chlordiazepoxide, diazepam and muscimol inhibited FTA-induced abnormal behaviors. These findings suggest that both dopaminergic and gamma-aminobutyric acid (GABA)-ergic systems are involved in FTA-induced abnormal behaviors. FTA-induced abnormal behaviors may be useful as a common experimental model for the primary evaluation of anticonvulsants, antipsychotic drugs and anxiolytic drugs.
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PMID:Abnormal behavioral effects elicited by a neurotropic mycotoxin, fumitremorgin A in mice. 615 72

The purpose of this study was to correlate the chlordecone-elicited tremor activity with alterations of brain neurotransmitters. A single injection of chlordecone (80 mg/kg, ip) significantly increased the brain levels of 5-hydroxyindoleacetic acid (5-HIAA) but did not affect the concentrations of dopamine, dihydroxphenylacetic acid, aspartate, taurine, glutamate, glycine, and gamma-aminobutyric acid (GABA). There was a dose- and time-related correlation between the increases in striatal 5-HIAA levels and tremor after chlordecone treatment. A subsequent study with pargyline indicated that the increase in striatal 5-HIAA level represented an increase in the turnover of serotonin. This study plus the previous finding that pizotifen (BC-105), a serotonin receptor blocker, attenuated chlordecone-elicited tremor strongly suggests a possible involvement of the serotonin system in mediating the tremor elicited by this insecticide.
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PMID:Effects of chlordecone exposure on brain neurotransmitters: possible involvement of the serotonin system in chlordecone-elicited tremor. 620 Sep 57


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