A number of recent studies have detected gamma-aminobutyric acid (GABA) in brain microdialysates by measuring an electroactive o-phthaldialdehyde (OPA)-alkylthiol derivative using HPLC with electrochemical detection. A particular problem of this approach is the stench of the thiol reagents involved, and the poor stability of the electroactive GABA derivative. Here we ...

The conversion of 5-hydroxytryptamine to several potential metabolites was examined in the annelid earthworm (Lumbricus terrestris). 5-hydroxytryptamine and some related amines were found to be present in several tissues of the earthworm. Injection of 5-hydroxytryptamine into the body cavity of the earthworm resulted in the production of a gamma-glutamyl conjugate ...

gamma-Carboxyglutamic acid (Gla)-containing proteins are extracellular proteins with enhanced cation or mineral-binding properties. Discovery of new Gla-containing proteins is facilitated by methods that decrease the number of steps and time involved in assaying for Gla. Reaction of 4-diazobenzenesulfonic acid (DBS) and Gla or Gla-containing proteins produces an intensely red-colored product. ...

Neuropeptide Y (NPY), peptide YY (PYY), and galanin are found throughout the central nervous system with appreciable levels occurring in the striatum. In this study we have investigated the effects of these peptides on the potassium-stimulated release of endogenous neurotransmitter amino acids from slices of rat striatum. The release of ...

We have examined potential functions of nitric oxide (NO) within the paraventricular nucleus (PVN) in urethan-anesthetized male Sprague-Dawley rats. Initial experiments demonstrated microinjection of 50 pmol of the NO donor, sodium nitroprusside (SNP), directly into the PVN resulted in significant decreases in mean blood pressure (BP) (-3,312 +/- 1,189 mmHg/s ...

The various possibilities for manipulating the gamma-aminobutyric acid (GABA) system to augment GABAergic inhibition have been surveyed with reference to the relevant antiepileptic compounds that have been successfully or unsuccessfully investigated in relation to these different mechanisms of action. The first clinical studies of tiagabine (TGB), a novel GABA-uptake inhibitor ...

Tomato (Lycopersicon esculentum L.) plants were sprayed with aqueous solutions of isomers of aminobutyric acid and were either analyzed for the accumulation of pathogenesis-related (PR) proteins or challenged with the late blight fungal agent Phytophthora infestans. The [beta] isomer of aminobutyric acid induced the accumulation of high levels of three ...

Tiagabine (TGB), a specific gamma-aminobutyric acid (GABA)-uptake inhibitor, is a potential new antiepileptic drug with a novel mechanism of action. In animal models of epilepsy as well as in a placebo-controlled trial in patients with complex partial seizures, TGB showed significant anticonvulsant effects. TGB was well tolerated by most patients.

A double blind placebo-controlled study of two doses of gamma-linolenic acid, provided by evening primrose oil (EPO, Epogam, Searle, U.K.), in children with atopic dermatitis was performed: 1) to examine the effect of gamma-linolenic acid administration on the clinical status of children with atopic dermatitis and abnormalities of IgE-mediated immune ...

The tissue distribution of 99mTc-labeled vesicles prepared from synthetic amphiphiles containing an amino acid residue (synthetic liposomes) after intraperitoneal (i.p.) injection in Ehrlich solid tumor-bearing mice was investigated. Synthetic liposomes were labeled with 99mTc using stearylamine-diethylenetriaminepentaacetic acid as a chelator. The accumulation of the synthetic liposomes in liver decreased and ...

A former study indicated that hypoxic-ischemic encephalopathy in rat sustained during early postnatal life may result in permanent epileptic activity in the baseline electroencephalogram. We, therefore, investigated whether the presumed higher firing frequency and metabolic activity of neurons in such hypoxia-damaged cortical areas would be reflected by an enhanced light ...

Morphological and glutamic acid decarboxylase (GAD) immunocytochemical properties of the dorsal part of the lateral geniculate nucleus were investigated in reptiles, Caiman crocodilus. GAD immunoreactive neurons, although sparse, were found in the dorsal part of the lateral geniculate nucleus. In addition, puncta and fibers immunoreactive for GAD were also observed ...

A 32 year old patient with refractory complex partial seizures was treated with vigabatrin for 3.5 years. Before starting treatment and at 42 months, lumbar punctures were done and the CSF analyzed for amino acids including GABA. Although the patient experienced a 50% seizure reduction, he underwent a left sided ...

Immunocytochemical methods were used on serial sections to study the glycine- and gamma-amino butyric acid (GABA)ergic innervations of the teleost Mauthner (M) cell. We found different distributions for the boutons containing the two amino acids. Endings filled with GABA predominate on the distal portion of the lateral dendrite (LD) while ...

1. The use of an Ultrogel AcA 54 gel-filtration column separates camel lens cortex low molecular weight proteins into four peaks containing beta s-, gamma 1-, gamma 2- and gamma 3-crystallins. 2. The molecular weight of beta s-crystallin corresponded to 29 kDa on SDS-PAGE and showed three major bands between ...

Interferon-gamma (IFN-gamma) specifically induced the uptake of the unsaturated fatty acid [14C]linoleic acid into membrane phospholipids of the murine macrophage-like P388D cell lineage, but did not alter the incorporation of the saturated fatty acid [14C]stearic acid. Spin label ESR spectroscopy was used to examine any effects of these IFN-gamma-induced changes ...

Glutamic acid decarboxylase (GAD) is the enzyme that synthesizes the neurotransmitter gamma-aminobutyric acid (GABA) in neurons and in pancreatic beta cells. It is a major target of autoimmunity in Stiff-Man syndrome (SMS), a rare neurological disease, and in insulin-dependent diabetes mellitus. The two GAD isoforms, GAD-65 and GAD-67, are the ...

L-Amino acids are potent olfactory stimuli for Atlantic salmon. A plasma membrane fraction, previously shown to be rich in amino acid binding sites, was prepared from olfactory rosettes of Atlantic salmon (Salmo salar) and utilized to investigate the role of phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis in olfactory signal transduction. A cocktail ...

Prothrombin has 10 gamma-carboxyglutamic acid residues which are essential for the metal ion binding properties and membrane binding function of the protein. To assess the importance of each gamma-carboxyglutamic acid residue we made, by site directed mutagenesis, a series of mutant human prothrombins each with a single glutamic acid to ...

Effects of taurine on endogenous aspartic acid (Asp), glutamic acid (Glu) and gamma-aminobutyric acid (GABA) release has been investigated using synaptosomes prepared from rat cerebral cortex. Although basal release of these amino acids was not affected, taurine inhibited KCl (30 mM)-evoked overflow of Asp, Glu and GABA in a concentration-dependent ...

OBJECTIVE: To study the effect of intravenous lipid emulsions enriched with gamma-linolenic acid on plasma fatty acids and series-2 prostaglandins to determine if the slow conversion of linoleic acid by delta-6-desaturase to gamma-linolenic acid could be bypassed to provide substrate for the formation of dihomo-gamma-linolenic acid, the immediate precursor for ...

Cigarette smoking is a main source of cyanide in human body, which can be taken as a risk factor of cataract formation. In this study, combined gas chromatography and mass spectrum (GC/MS) was used to determine the amino acid hydantoin after the incubation of soluble human lens gamma-crystallins with cyanate. ...

Time- and dose-response analyses were undertaken to investigate the effects of the substituted hydrazine monoamine oxidase (MAO) inhibitors iproniazid and nialamide on the following: MAO-A and -B activity; levels of gamma-aminobutyric acid (GABA), alanine (ALA), and the neurotransmitter amines dopamine, noradrenaline, and 5-hydroxytryptamine (serotonin) and their acid metabolites; and the ...

gamma-Hydroxybutyric acid is a naturally occurring compound which induces bilaterally synchronous spike and wave discharges in rats. The gamma-hydroxybutyric acid model of absence seizures simulates clinical absence seizures behaviorally as well as electrographically. The present study was undertaken in order to establish the role of the high-affinity gamma-hydroxybutyric acid binding ...

The metabolism of 15-(4'-iodophenyl)pentadecanoic acid (IPPA) in the heart muscle is commonly believed to end at 4-iodobenzoic acid as the main and final product of beta-oxidation. However, investigation of the metabolic fate of IPPA in Langendorff rat hearts using high pressure liquid chromatography (HPLC) and negative fast atom bombardment mass ...

The effects of a neonatal dopaminergic deafferentation with the neurotoxin 6-hydroxydopamine (6-OHDA) on endogenous tissue levels of catecholamines, indoleamines, and amino acids were investigated in discrete rat brain regions. After producing the lesion at postnatal day 3 by intraventricular injections of 6-OHDA, with a desipramine pretreatment to protect noradrenaline neurons, ...

Sustained accumulation of excitatory amino acids and other neuroactive substances may contribute to the delayed progression of infarction in focal ischemia. Following occlusion of the left middle cerebral artery (MCAO), extracellular amino acid and purine catabolite concentrations as well as local CBF were repeatedly monitored for up to 15 h ...

In order to investigate the effect of cycloartenol ferulic acid ester (CFE, CAS 21238-33-5), a component of gamma-oryzanol which is a phytosterol derived from rice bran, on the central nervous system, a variety of pharmacological tests were performed. It was shown that CFE had a suppressant effect on the central ...

The effects of gamma-aminobutyric acid (GABA) on the spontaneous release of endogenous glutamic acid (Glu) or aspartic acid (Asp) and the effects of Glu on the release of endogenous GABA or [3H]GABA were studied in superfused rat cerebral cortex synaptosomes. GABA increased the outflow of Glu (EC50 17.2 microM) and ...

Localized 1H NMR spectroscopy in conjunction with J editing was used to measure the concentration of gamma-aminobutyric acid (GABA) in the occipital lobe of four control human volunteers and four epileptic volunteers who were receiving the drug vigabatrin. The GABA concentration measured in four nonepileptic subjects was 1.1 +/- 0.1 ...

We describe a patient with presenile-onset cerebral adrenoleukodystrophy presenting as Balint's syndrome and dementia. There were demyelinating MRI changes in the parieto-occipital white matter bilaterally, including the splenium of the corpus callosum. Therapeutic trials using 1-deamino-(8-D-arginine)-vasopressin, very long-chain fatty acid-free diet, and gamma-globulin were of no benefit.

The genotoxic potential of methyl mercury chloride (MMC) was investigated in human lymphocyte cultures by tests for chromosomal aberrations and sister chromatid exchange. The protective role of gamma-linolenic acid, a derivative of dietary essential fatty acid, on MMC-induced genetic damage was evident from the reduced frequency of aberrations and sister ...

Spotted mackerel protamine, scombrine, was isolated from the sperm of a spotted mackerel (Scomber australasicus) by extraction with sulfuric acid and fractionated into one major (scombrine II) and one minor (scombrine I) components by chromatography on CM-Sephadex C-25. Scombrine II gave a single band, whereas scombrine I gave three bands ...

The N-4,4-diphenyl-3-butenyl derivative of the glial selective gamma-aminobutyric acid (GABA) uptake inhibitor 4,5,6,7-tetrahydroisoxazolo [4,5-c]pyridin-3-ol (N-DPB-THPO), was tested for its ability to block sound-induced seizures in the audiogenic seizure-susceptible Frings mouse model of epilepsy. Following intracerebroventricular (i.c.v.) administration, N-DPB-THPO blocked tonic hindlimb extension in a dose- and time-dependent manner. At the ...

The platelet levels of serotonin and the amino acids aspartic acid, glutamine, glutamic acid and gamma-aminobutyric acid were measured in 18 drug-free autistic (DSM-III criteria) and 14 age-matched healthy children. Serotonin was significantly increased while the amino acids aspartic acid, glutamine, glutamic acid and gamma-aminobutyric acid were significantly decreased in ...

A partially purified toxin from the marine sponge Haliclona viridis was studied for its effect on the presynaptic release mechanism of 3H-gamma-aminobutyric acid from nerve terminals of the external plexiform layer of rat olfactory bulb. Previously, the toxin of H. viridis was shown to block the resting potassium conductance in ...

The rho 2 receptor for gamma-aminobutyric acid (GABA) induces GABA-gated currents when expressed as a homooligomer in Xenopus oocytes. rho 2 responses display pharmacological profiles similar to those of expressed rho 1 receptors, although responses were slower, most agonists were more potent at rho 2 and Im values for the ...

gamma-Linolenic acid (GLA) production using a high GLA producing marine green alga, Chlorella sp. NKG 042401, was studied. GLA was presented in the galactolipid fraction (37.9%/total fatty acids). The effects of growth conditions on GLA production were studied. Optimum salinity for GLA production was 5 g l-1, at which salinity ...

Human IgG allotypic markers Gm(a)[Glm(1)], Gm(x)[Glm(2)]; Gm(f)[Glm(4)], Gm(b)[G3m(5) and (11)] and Gm(g)[G3m(21)] were studied after chemical modification of IgG histidines by diethylpyrocarbonate, tyrosines by N-acetylimidazole and lysines by formaldehyde and sodium borohydride. Degrees of substitution were estimated by trinitrobenzenesulfonic acid assay. IgG of known Gm phenotype isolated from serum of ...

The amino acid gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in brain, and GABAergic neurons have been proposed to play a major role in basal ganglia physiology. In the neostriatum (caudate putamen), medium-sized aspiny interneurons, as well as neostriatal output neurons that project to several brain regions, use GABA ...

A method for measuring gamma-aminobutyric acid (GABA) in human cerebrospinal fluid (CSF) by isocratic HPLC with electrochemical detection is described. The method is based on precolumn derivatization of GABA with o-phthaldialdehyde (OPA) and tert-butylthiol (t-BT), separation of the GABA-OPA complex on a reversed-phase column, and quantitation by means of a ...

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), 1-methyl-4-phenylpyridinium iodide (MPP+) and gamma-vinyl-gamma-aminobutyric acid (gamma-vinyl GABA) are drugs demonstrated to alter catecholamine or gamma-aminobutyric acid (GABA) concentrations in vertebrate nervous tissue. MPTP and MPP+, which are potent and selective vertebrate neurotoxins, are effective in depleting noradrenaline and dopamine concentrations in goldfish. However, only MPP+ depletes dopamine ...

Comparison of data based on the reverse-phase HPLC with two ion-pairing reagents, trifluoroacetic acid (TFA) and heptafluorobutyric acid (HFBA), together with the use of two antibodies, has allowed us to identify the various tachykinins in the bovine adrenal medulla. The results show that substance P-like, neurokinin B-like, and neurokinin A-like ...

Gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter in the mammalian central nervous system, is produced from glutamic acid in a reaction catalysed by glutamic acid decarboxylase. The sequential actions of GABA-transaminase (converting GABA to succinic semialdehyde) and succinic semialdehyde dehydrogenase (oxidizing succinic semialdehyde to succinic acid) allow oxidative metabolism of ...

We synthesized the selenium analog of glutathione disulfide by a liquid phase method and named it glutaselenone (i.e., gamma-L-glutamyl-L-selenocysteinylglycine) diselenide. The selenol of selenocysteine was protected by the p-methoxybenzyl group, which was removed by acidolysis with trifluoroacetic acid in the presence of thioanisol. The overall yield of the final product, ...

4-Aminophenol (para-aminophenol; PAP) causes selective necrosis to the S3 segment of the proximal tubule in experimental animals. The mechanism of PAP nephrotoxicity has not been fully elucidated, although it has been suggested to involve glutathione (GSH)-dependent S-conjugation followed by processing by the enzyme gamma-glutamyl transpeptidase (gamma GT) to the corresponding ...

Glutamate and gamma-aminobutyrate (GABA) are two neurotransmitters that appear to play an important role in the hypothalamic suprachiasmatic nucleus (SCN) and in the adjacent areas of the medial hypothalamus. Converging evidence based on ultrastructural immunocytochemistry, molecular biology, calcium imaging, and electrophysiology suggests not only that GABA and glutamate are used ...

Gamma-aminobutyric acid (GABA) is a potent amino acid neurotransmitter with various physiologic effects throughout the body. Over the past 40 years it has become evident that the mammalian liver contains high concentrations of GABA which are carefully regulated by a series of hepatic metabolic pathways and a specific sodium-dependent active ...

The effects of GABAA (muscimol) and GABAB (baclofen) receptor agonists on spontaneous motor activity and food consumption of rats were compared to those produced by taurine and related compounds (3-aminopropanesulphonic acid, 5-aminovaleric acid, and guanidinoethanesulphonic acid). Local application of muscimol into the nucleus raphe dorsalis caused a dose-dependent increase in ...

Fenbufen-induced skin rash was investigated by determining the metabolism of the drug to reactive products. At least five lipophilic products (unidentified), the active metabolite of this drug, biphenyl acetic acid (BPAA), and a gamma-hydroxylated derivative (gamma-hydroxy[1,1'-biphenyl]-4-butanoic acid) were identified in keratinocytes in vitro and in skin of rats and guinea ...