Determination Of Gamma-aminobutyric Acid Research Articles

Порушення метаболізму нейромедіаторів у дітей із розладами аутистичного спектра (огляд літератури та власні дані)

Тоді, коли збільшується число дітей, хворих на розлади аутистичного спектра (РАС), зростає кількість досліджень, в яких вивчаються клінічні особливості перебігу, патогенез, етіологічні фактори і методи лікування даного захворювання. Єдиної думки щодо етіології та патогенезу РАС на сьогодні не існує. У статті подано сучасні дані літератури, що висвітлюють проблему порушень обміну нейромедіаторів у дітей із РАС. Також наведені дані, отримані при визначенні концентрації гамма-аміномасляної кислоти (ГАМК) в плазмі крові дітей із когнітивною епілептиформною дезінтеграцією (n = 45) і дітей із РАС без епілептичних нападів (n = 15). За результатами дослідження відзначалося зниження середньої концентрації ГАМК у дітей із когнітивною епілептиформною дезінтеграцією порівняно з контрольною групою (n = 12). Істотних відмінностей у середній концентрації ГАМК між групою дітей із РАС без епілептичних нападів і контрольною групою виявлено не було (p < 0,001). Отримані нами результати і огляд літературних даних дозволяють стверджувати про необхідність застосування в лікуванні дітей із РАС препаратів, що регулюють метаболізм нейромедіаторів, особливо ГАМК.

Determination of Gamma-aminobutyric Acid in Germinated Brown Rice by HPTLC

Gamma-aminobutyric acid (GABA) is a neurotransmitter in the central nervous system, and regulates blood pressure, heart rate, sensation of pain and anxiety, lipid levels in serum and assist in insulin secretion to prevent diabetes. GABA, a bioactive component is known to accumulate in rice during germination process. In this study, an attempt was made to investigate the effect of germination process on GABA levels in selected local rice cultivars (Swarna and Lalat) of Odisha, India. High-performance thin layer chromatography (HPTLC) was used for determination of GABA concentration in germinated brown rice (GBR), white rice (WR) and brown rice (BR). Results showed that GABA content in GBR is 1.5 and 2 times more than that in BR and WR, respectively.

Determination of Gamma-aminobutyric Acid in Germinated Brown Rice by HPTLC

Gamma-aminobutyric acid (GABA) is a neurotransmitter in the central nervous system, and regulates blood pressure, heart rate, sensation of pain and anxiety, lipid levels in serum and assist in insulin secretion to prevent diabetes. GABA, a bioactive component is known to accumulate in rice during germination process. In this study, an attempt was made to investigate the effect of germination process on GABA levels in selected local rice cultivars (Swarna and Lalat) of Odisha, India. High-performance thin layer chromatography (HPTLC) was used for determination of GABA concentration in germinated brown rice (GBR), white rice (WR) and brown rice (BR). Results showed that GABA content in GBR is 1.5 and 2 times more than that in BR and WR, respectively.

Determination of Gamma-aminobutyric Acid (GABA) Content in Grains and Cruciferous Vegetable Seeds

Gamma aminobutyric acid (GABA) has great physiological functions, mainly as a major inhibitory neurotransmitter in the brain, which makes it important for the development of functional foods. This study detected GABA in grains and cruciferous vegetable seeds by using HPLC after pre-column on-line derivatization with diode array detection (DAD) and fluorescence detection (FLD). The limit of quantitation was 2.94 and 2.86 µg/mL with DAD and FLD, respectively. GABA recoveries ranged from 98.8 to 111.2% on both detectors. Intra and inter-day precision showed relative standard deviations, generally, less than 10% for both DAD and FLD. GABA was determined in different grains (flaxseeds, white quinoa seeds, and buckwheat) and cruciferous vegetable seeds (broccoli, kale, daikon radish, mustard, cabbage, and brussels sprouts). Organic broccoli seeds contained the highest amount and mustard seeds the least amount of GABA in the Brassica family with none being detected in organic white quinoa and flaxseeds. A statistically significant difference (p < 0.05) exists between the various lots of the broccoli seeds. GABA is important as a natural source in functional foods.

Capillary Gas Chromatographic Determination of Gamma Aminobutyric acid and Putrescine in Cerebrospinal Fluid using Trifluoroacetylacetone as Derivatizing Reagent

determination of gamma aminobutyric acid (GABA) and putrescine (Put) using trifluoroacetylacetone (FAA) as derivatizing reagent from Cerebrospinal Fluid (CSF) samples prior to their gas chromatographic- flame ionization detector (GC-FID) analysis. GABA, Put, cadaverine (Cad) and tyramine (TY) as imitative of FAA extracted from the column HP-5 (30 m x 0.32 mm i.d) at temperature 110 oC for 1 min, tracked by heating rate 25 oC to 260 oC /min. The detection was carried out by FID with segregate ratio 10:1, v/v with whole run time 10 min. The proposed method showed linear calibration range between 2.5-50 µg/mL with low limit of detection 1.0 - 2.5 µg/mL analogous to 0.1 ng to 0.25 ng for selected Put, Cad, GABA, and TY. The method based on the pre-concentration was used for the determination of GABA and Put from CSF of human being and amounts found were 0.25- 0.56 µg/mL and 0.16 - 0.41 µg/mL with relative standard deviation (RSD) within 0.8 - 1.1 and 1.1 - 1.5 %, respectively. Many of aminoacids tested, separated completelyand did not variate the determinations of GABA and Put.

Enzymatic Flow Injection Determination of Gamma-Aminobutyric Acid

Abstract γ-Aminobutyric acid (GABA) was determined by using flow injection analysis with a column of GABAse immobilized on glass beads. The NADPH produced was monitored fluorometrically. At a flow rate of 0.8 ml/min, peak heights were linear in the range 1-500 μM, and samples could be injected every minute. Nearly 100 % recovery of GABA was observed when GABA was added to infusions of green tea. ∗Permanent address: National Research Institute of Vegetables, Ornamental Plants and Tea, 2769 Kanaya, Shizuoka 428 JAPAN

Fast HPLC Estimation of γ‐Aminobutyric Acid in Microdialysis Perfusates: Effect of Nipecotic and 3‐Mercaptopropionic Acids

A method for rapid, automated (less than 5 min), and sensitive (detection limit 50 fmol/10 microliter) determination of gamma-aminobutyric acid (GABA) is described. The method is based on precolumn derivatization with o-phthaldialdehyde/t-butylthiol reagent and separation by reverse-phase HPLC with electrochemical detection under isocratic conditions. A 100 X 4 mm Nucleosil 3 C18 column was used; the mobile phase consisted of 0.15 M sodium acetate, 1 mM EDTA (pH 5.4), and 50% acetonitrile; the flow rate was 0.8 ml/min. The potential of the glassy carbon working electrode was +0.75 V. The method allows for the monitoring of GABA levels in the extracellular fluid sampled by microdialysis as documented in the present study when 0.5 mM nipecotic acid is infused via the probe, or 3-mercaptopropionic acid is injected at a dose of 100 mg/kg i.p. There was a 15-fold increase of extracellular GABA after nipecotic acid, whereas in the second case the inhibition of GABA synthesis was followed by a 74% decrease of GABA as compared to basal levels.

A specific and sensitive determination of gamma aminobutyric acid in CSF and brain tissue by gas chromatography-mass spectrometry

The determination of γ-aminobutyric acid (GABA) in cerebrospinal fluid and brain extracts is described. Its heptafluorobutyryl-isobutanol derivative was measured both by electron impact and chemical ionization mass fragmentography using GABA-d 6 as internal standard. The derivatization product is stable for several days. The method is sensitive (1 ng absolute in cerebrospinal fluid and 30 pg in standard GABA solutions) and specific, when chemical ionization mode is applied. Normal values of GABA are in rat brain extracts (1.40±0.32 μmol/g fresh weight) and human CSF (18.3±10.0 ng/ml).

EDTA inhibits in vitro increases in the GABA content of human CSF.

Aliquots of pooled samples of lumbar CSF from patients with neurological disorders were subjected to storage at room temperature for different periods of time up to 4 days. The determination of gamma-aminobutyric acid (GABA) levels in CSF by a radioreceptor assay showed a progressive increase in GABA content with time, which could be counteracted by addition of EDTA (5 mM). Similar results were obtained with cisternal CSF collected from dogs. The in vitro increases in GABA levels of untreated CSF might relate to the action of a metal-enzyme which is inhibited by metal-trapping substances such as EDTA.

Gamma-aminobutyric acid determination in human cerebrospinal fluid by mass-fragmentography.

Gamma-aminobutyric acid determination in human cerebrospinal fluid by mass-fragmentography.

A highly specific and sensitive determination of gamma-aminobutyric acid by gas chromatography mass spectrometry.

A procedure for the identification and quantification of picomole quantities of gamma-aminobutyric acid in tissue samples is given. This procedure combines the chemical specificity of dinitrophenylation with that of gas chromatography mass spectrometry to eliminate the interferences encountered with other direct derivatization procedures. Only a limited number of dinitrophenyl amino acid ethyl esters and some fatty ethyl esters are detected in the solution used for analysis. Identification is based on retention time and on the relative abundances of the three major ion fragments of the gamma-aminobutyric acid derivative. Quantitation is accomplished using isotope dilution techniques with [2H2]gamma-aminobutyric acid as an internal standard. The procedure has been successfully applied to samples of human cerebrospinal fluid and to extracts of ganglia from the mollusc, Aplysia californica.

The determination of gamma-aminobutyric acid in brain

A simple method for the determination of γ-aminobutyric acid in brain tissue is described. Two columns of ion-exchange resin are used. An extract of rat brain is first passed through Amberlite CG-50, which removes basic amino acids and amines. The effluent from this column is then passed through a column of Dowex 50 buffered at pH 3.1. Elution from this column with pH 3.1 buffer removes other interfering amino acids from the resin. Good recoveries of GABA added alone, in a mixture of amino acids, or mixed with a true brain extract were obtained. Values of the GABA content of brain obtained by this method agree well with those reported in the literature.