• Biomedical Science Letters
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• v.12 no.2
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• pp.113-118
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• 2006

Major pelvic ganglia (MPG) in rats are an unique autonomic ganglia, containing both sympathetic and parasympathetic neurons related with the function of bladder, penis and bowel. It has been widely known that ionotropic $GABA_A$ receptors are the molecular target of $\gamma$-aminobutric acid (GABA), a major inhibitory neurotransmitter in central nervous system. However, their functions and regulations of $GABA_A$ receptors expressed in autonomic ganglia have been poorly understood. 1 examined the modulatory role of adenylyl cyclase (AC) and protein kinase A(PKA) on $GABA_A$-induced inward currents in the neurons of rat MPG. $GABA_A$ receptors were identified using immunofluorescent labeling in the rat major pelvic ganglion. Electrophysiological experiments were performed to record the activities of $GABA_A$ receptors. $GABA_A$ receptors were expressed only in sympathetic neurons. GABA induced marked inward currents in a concentration-dependent manner. Mucimol ($5{\mu}M$), a $GABA_A$ receptor agonist induced inward currents were significantly reduced in the presence of SQ 225361 $20{\mu}M$, a AC inhibitor and myristoylated PKA inhibitor 100 nM. In addition, forskolin ($1{\mu}M$), AC activator, augmented the GABA induced currents. The activation of AC/PKA-dependent pathway could involve in the regulation $GABA_A$ receptors, expressed only in sympathetic neurons of rat MPG. These findings are helpful for the better understanding the function of various pelvic organs innervated by MPG.

• Korean journal of food and cookery science
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• v.23 no.3 s.99
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• pp.409-412
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• 2007

The aim of this study was to examine the content of bioactive component, ${\gamma}$-aminobutyric acid (GABA) in 7 commercial green teas. The teas were grown in different regions in Sourhtern Korea, and were picked during the middle of the season. The green tea extracts were each derivatized with 6-aminoquinolyl-N-hydroxy-succinimidyl carbamate(AccQ${\cdot}$Fluor), and GABA was detected by a fluorescence detector at arf excitation of 250 nm and emission of 395 nm. The GABA contents varied depending on the regions where the green tea samples were produced. There was no significant difference in GABA contents between samples A and C, where it ranged from from 45.21${\pm}$0.99 (nmol/g) to 63.83${\pm}$0.61 (nmol/g): however, a significantly different amount of GABA was found in the green tea produced in B. The highest GABA content was 210.67${\pm}$0.85 (nmol/g), whereas the lowest content was 3.88${\pm}$0.71 (nmol/g). This variation in GABA contents was probably due to the regional differences, even within the same location, as well as the processing technology, which may retain or develop more GABA components in the final green tea.

• International Journal of Oral Biology
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• v.30 no.3
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• pp.91-98
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• 2005

Gamma-aminobutyric acid (GABA) is known as an inhibitory neurotransmitter in the neurons of the central nervous system. However, its detailed action mechanisms in the rostral gustatory zone of the nucleus tractus solitarius (rNTS) have not been established. The present study was aimed to investigate the distribution, role and action mechanisms of GABA in rNTS. Membrane potentials were recorded by whole cell recordings in isolated brain slices of the rat medulla. Superfusion of GABA resulted in a concentration-dependent reduction in input resistance in the neurons in rNTS. The change in input resistance ws accompanied by response to a depolarizing pulse were diminished by GABA. Superfusion of the slices with either $GABA_A$ agonist, muscimol, $GABA_B$ agonist, baclofen or $GABA_C$ agonist, TACA, decreased input resistance and reduced the nerve activity in association with membrane hyperpolarization. It is suggested that inhibitory signals playa role in sensory processing by the rNTS, in that GABA actions occur through activation of $GABA_A,\;GABA_B\;and\;GABA_C$ receptor. These results suggest that GABA has an inhibitory effect on the rNTS through an activation of $GABA_A,\;GABA_B\;and\;GABA_C$ receptors and that the GABAergic inhibition probably plays an important role in sensory processing by the rNTS.

• Journal of Dairy Science and Biotechnology
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• v.27 no.1
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• pp.45-51
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• 2009

$\gamma$-aminobutyric acid (GABA) is a ubiquitous nonprotein amino acid that is produced primarily by $\alpha$-decarboxylation of L-glutamic acid (Glu) catalyzed by the enzyme glutamate decarboxylase (GAD). It is well known as a neurotransmitter that regulates inhibitory neurotransmission in the mammalian central nervous system. In addition, GABA has been proved to be effective for lowering blood pressure in mammals. This paper is intended to provide basic information about GABA, including the functional and biological activity of GABA, GABA production by lactic acid bacteria, and the utilization of GABA in the production of dairy products.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.228-234
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• 2022

Various types of tea have been cultivated to obtain different flavors and enhance their functional properties. The objective of this study was to investigate the physicochemical properties of γ-aminobutyric acid (GABA) teas produced from commercial Korean green, white, and black teas. The concentration of total minerals was reduced in GABA green tea and GABA white tea but was improved in GABA black tea. The essential, non-essential, and total free amino acid contents were remarkably increased in the GABA teas. The amino acid GABA content was increased by 561.00 and 294.20 times in GABA white tea and GABA black tea, respectively. The antioxidant potential was not reduced, although the total polyphenol and total flavonoid contents decreased in GABA green tea and GABA black tea. The results indicated that the overall nutritional value of commercial green, white, and black teas could be improved by processing them into GABA teas.

• Journal of Sericultural and Entomological Science
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• v.40 no.1
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• pp.13-16
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• 1998

From mulberry root bark of 13 various varieties, ${\gamma}$-Aminnobutyric acid(GABA) contents were examined on HPLC analyzer. GABA contents in mulberry root bark were affected by genotypes. Average GABA content of the 13 mulberry varieties was 2.19 mg/gDW. GABA content of the varieties ranged from 1.70 to 2.62 mg/gDW. Among the three genotypes, GABA content of the Morus Lhou was higher than the other genotype. In GABA content Hongolppong was the highest with 2.62 mg/gDW on the 13 varieties of mulberry root bark.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.1
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• pp.35-40
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• 2018

${\gamma}$-Aminobutyric acid (GABA) has antihypertensive and anti-stress effects on humans. The present study aimed to investigate the effect of glutamate concentration, bran content, and barley cultivars on GABA production and determine the optimal reaction condition. Barley bran resulted in higher GABA productivity compared with that of rice bran. The higher the bran content, the higher was the GABA productivity. Furthermore, high glutamate concentration resulted in high GABA production. However, there was a decrease in the glutamate conversion rate. The production of GABA varied with temperature and barley cultivar. The optimal condition for GABA production using barley bran was 0.15 g/mL barley content, 10 mM glutamate concentration, and $20^{\circ}C$ reaction temperature. Under optimal condition, the GABA concentration was 10.34 mM, and glutamate conversion rate was 75.1%. Furthermore, the GABA productivity of the GABA production reaction using barley bran differed depending on the cultivar. Dasong and Yeongbaekchal showed higher GABA productivity than that by other cultivars.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.761-764
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• 2004

Effects of pretreatment conditions on ${\gamma}-aminobutyric$ acid (GABA) contents of brown rice and germinated brown rice were investigated. As steeping time increased, GABA contents of brown rices increased gradually. The highest GABA content, 3.33mg/100g, was found in brown rice steeped at $40^{\circ}C$ for 8 hr. GABA content of brown rice decreased significantly at pH 8 (p<0.05), but changed slightly at pH of steeping solution ranging 4-7. Steeping of brown rices in glutamate solution increased GABA contents. Brown rice steeped in glutamate solution at 200-300 ppm showed GABA content between $4.09{\pm}0.48-4.11{\pm}0,47mg/100g$, which was much higher than that of untreated brown rice. Anaerobic treatment of brown rices using $N_2$ gas increased GABA contents, ranging from $4,70{\pm}0.49\;to\;4.92{\pm}0.83mg/100g$. Germinated brown rice steeped in glutamate solution under anaerobic condition had GABA content of $5.92{\pm}0.72mg/100g$, two-fold higher than that of untreated brown rice, $3.05{\pm}0.67mg/100g$. Optimum pretreatment condition established in this study could significantly increase GABA content in germinated brown rice.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.142-146
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• 2010

Relatively large amounts of GABA can be produced by the fermentation of rice bran. Therefore, this study was conducted to investigate the effects of GABA on the secretion of melatonin and serotonin for the development of a sleep inductive compound. The secretion levels of melatonin and serotonin from mice were found to be $3.425{\pm}0.182\;pg/mL$ and $5.37{\pm}0.963\;ng/mL$, respectively, in response to feeding 120 mg/mL of GABA while they were $2.607{\pm}0.41\;pg/mL$ in the control. The secretion of both melatonin and serotonin was increased up to the 13.51% and 34.99%, respectively, when compared to the negative control. However, the feeding of milk alone did not have a great effect on the melatonin and serotonin secretions. Conversely, feeding of milk with GABA enhanced the secretion of serotonin. The amounts of both melatonin and serotonin secreted increased with respect to the increase in GABA concentrations during feeding. Interestingly, the induction level of melatonin was relatively higher than that of serotonin in response to feeding 120 mg/mL of GABA. This is the first study to report that GABA has an ability to induce sleep related hormones in mice; therefore, it has the potential for use as a natural sleep aid.

• KSBB Journal
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• v.29 no.6
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• pp.426-431
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• 2014

pH controlled batch reactor and bubble column reactors have been developed in this research. They were used to produce high concentration of GABA and to determine optimal pH for GABA production. Glutamate decarboxylase (GAD) was isolated from recombinant E. coli and used for GABA production from monosodium glutamate (MSG). pH control was inevitable because the pH increased with MSG consumption. GAD showed highest activity at acidic conditions at pH 5.5 but the optimal pH for GABA production was pH 6.0. When 1.5 mole of MSG was used as reactant, the 1.05 mole of GABA was produced after 10 hrs batch reaction. Using bubble column reactors, 80 % of MSG was converted to GABA for 6 hrs reaction and 1.2 mole of GABA was produced.