Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P80404 (GABA transaminase)
 786 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

gamma-Vinyl GABA, an irreversible inhibitor of GABA transaminase, was administered orally to five patients with catatonic or hebephreno-catatonic schizophrenia. Improvement of psychiatric symptoms was observed in four cases. The results are discussed in relation to previously reported attempts to increase the CNS gabaergic function of patients with schizophrenia.
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PMID:[Effects of gamma-vinyl GABA per os in 5 cases of hebephreno-catatonic schizophrenia]. 664 16

The pharmacologic treatment of many neuropsychiatric disorders (Alzheimer's disease, schizophrenia, depressive illness) has been targeted at the central hypothesis that defects in a single neurotransmitter system underlie the pathophysiology of the disease state. With the recognition that such treatments have not been efficacious consistently, recent drug development has been directed at altering other functionally linked neurotransmitters involved in these diseases. Using positron emission tomography, we have noninvasively investigated the effects of two noncholinergic drugs on the release of acetylcholine. By examining the effects of gamma-vinyl gamma-aminobutyric acid (GABA) (a GABA transaminase inhibitor) or altanserin (a serotonergic antagonist) on the regional binding of 11C-benztropine in the primate brain (Papio anubis), we demonstrated that drugs acting upon either GABAergic or serotonergic neurons produce profound regional changes in acetylcholine release. These findings indicate that the mechanisms of action and the subsequent therapeutic efficacy of these centrally acting drugs may be linked to their multitransmitter effects. This application of positron emission tomography represents an extremely promising experimental approach that can be directed towards elucidating abnormalities in neurotransmitter modulation relevant to disease progression and pharmacologic treatment.
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PMID:Modulation of central cholinergic activity by GABA and serotonin: PET studies with 11C-benztropine in primates. 851 23

A defect in neurotransmission involving gamma-amino butyric acid (GABA) in schizophrenia was first proposed in the early 1970s. Since that time, a considerable effort has been made to find such a defect in components of the GABAergic system. After a brief introduction focusing on historical perspectives, this paper reviews post-mortem and other biological studies examining the following components of the GABAergic system in schizophrenic subjects: the GABA biosynthetic enzyme, glutamate decarboxylase; free GABA; the GABA transporter; the GABAA, GABAB and benzodiazepine receptors; and the catabolic enzyme GABA transaminase. Additionally, post-mortem studies using morphology or calcium-binding protein to identify GABAergic neurons are also reviewed. Substantial evidence argues for a defect in the GABAergic system of the frontal cortex in schizophrenia which is limited to the parvalbumin-class of GABAergic interneurons.
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PMID:The GABAergic system in schizophrenia. 1213 41

gamma-Aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system. GABA is converted from glutamic acid by the action of glutamic acid decarboxylase (GAD) of which two isoforms exist GAD65 and GAD67. GABA then is broken down, both within the cell and in the synaptic cleft by GABA transaminase to form succinic semialdehyde. In turn, succinic semialdehyde is converted either to succinic acid by succinic semialdehyde dehydrogenase or into gamma-hydroxybutyric acid (GHB) by succinic semialdehyde reductase. Because GABA modulates the majority of inhibition that is ongoing in the brain, perturbations in GABAergic inhibition have the potential to result in seizures. Therefore, the most common disorder in which GABA is targeted as a treatment is epilepsy. However, other disorders such as psychiatric disease, spasticity, and stiff-person syndrome all have been related to disorders of GABAergic function in the brain. This review covers the roles of GABAergic neurotransmission in epilepsy, anxiety disorders, schizophrenia, stiff-person syndrome, and premenstrual dysphoric disorder. In the final section of this review, the GABA metabolite GHB is discussed in terms of its physiological significance and its role in epilepsy, sleep disorders, drug and alcohol addiction, and an inborn error of GABA metabolism, succinic semialdehyde dehydrogenase deficiency.
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PMID:GABA, gamma-hydroxybutyric acid, and neurological disease. 1289 48

Dysfunctions of glutamatergic and GABAergic neurotransmission are two important hypotheses for the pathogenesis of schizophrenia. Thus, genes in the pathway are candidates for schizophrenia susceptibility. Phosphate-activated glutaminase (GLS), glutamine synthetase (GLUL), glutamic acid decarboxylase (GAD), GABA transaminase (ABAT) and succinic semialdehyde dehydrogenase (ALDH5A1) are five primary enzymes in glutamate and GABA synthetic and degradative pathway. In order to investigate the possible involvement of these genes in the development of paranoid schizophrenia, we genotyped 80 paranoid schizophrenics from northern China and 108 matched controls by polymerase chain reaction (PCR) and restriction fragment length polymorphisms (RFLP) methods or directly sequencing of PCR product. Seven SNPs were found to be polymorphic in the population investigated. No significant differences in the genotype distributions or allele frequencies between patients and controls were found. Therefore, we conclude the polymorphisms studied in the five genes do not play major roles in pathogenesis of paranoid schizophrenia in the population investigated.
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PMID:An association study between polymorphisms in five genes in glutamate and GABA pathway and paranoid schizophrenia. 1564 43

In the mammalian central nervous system (CNS), the inhibitory GABAergic system is composed of different signaling molecules such as glutamate decaroxylase, vesicular GABA transporters, GABA receptors, GABA transporters and GABA transaminase. A prevailing view is that the balance between excitatory signaling mediated by glutamate and inhibitory signaling mediated by GABA plays a pivotal role in mechanisms underlying the modulation and maintenance of a variety of neural functions. Therefore, abnormalities in a GABAergic signaling molecule would lead to a crisis of severe symptoms relevant to a number of neuropsychiatric disorders. These include epilepsy, depression, schizophrenia, stiff-person syndrome, drug addiction and so on. In this review article, we will summarize recent studies on the relationship between the malfunction of GABAergic signaling molecules and the etiology of these neuropsychiatric disorders. We will also refer to novel strategies on GABAergic signaling molecules other than GABA receptors for therapeutic usefulness in the future.
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PMID:[Neuropsychiatric disorders and GABA]. 1565 2

We have recently suggested that platelets could be used as a model for neuronal receptors. In this paper we have investigated gamma-aminobutyric acid (GABA) metabolism and GABA receptors in platelets and in cultured neurons to see whether platelets' GABA mimics neuronal GABA receptor activities. We used the ELISA technique for detecting the GABA concentration in platelet rich plasma and cultured neurons. The functional effects of GABA and its receptor ligands on platelets were determined using an aggregometer. We found that the GABA concentration is 30% lower in platelets than in neurons and in both preparations GABA was metabolized by GABA transaminase (GABA-T). GABA potentiated calcium dependent platelet aggregation with a higher value in washed platelets suspension (WPS) then in platelet rich plasma (PRP). This effect was inhibited by benzodiazepines, calcium channel blockers and the selective phosphoinositide 3-kinase antagonist Wortmannin. GABA neurotransmission is involved in most aspects of normal brain function and can be perturbed in many neuropathologic conditions. We concluded that platelets could be further developed to be used as a peripheral model to study neuronal GABAergic function and its abnormality in diseases such as epilepsy and schizophrenia. Furthermore our results indicated that PI3-kinase is involved in calcium dependent GABA induced platelet aggregation as this synergistic effect is inhibited by Wortmannin in dose dependent manner.
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PMID:Investigating GABA and its function in platelets as compared to neurons. 1963 96