• The Korean Journal of Zoology
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• v.38 no.1
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• pp.66-73
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• 1995

Putative gamma aminobu%sic acid (GABA)-ersic elements in the basilar pontine nuclei were examined in the dos using an antiserum against GABA-glutaraldehvde-protein conjusBtes and the peroxidase-antiperoxidase method. GABA-immunoreactive neuronal somata in the basilar Pons exhibited various morphology with the majority being spindle-shaped or multipolar, while some were spheroidal. The size of GABA-orgic neuronal somata was relatively small (approximately $10-20\mum)$ in diameter. GABA-immunoreactive neurons were scattered throughout the pontine nuclei, but the midline region of the medial nucleus at the rostral pons, the lateral nucleus at mid-pontine levels, and the ventral nucleus at the caudal pons exhibited a relatively greater concentration of cell bodies. A sparse number of GABA-ergic neurons were observed within the cerebral peduncle and along the ventral borders of the basilar pons adjacent to the middle cerebellar peduncle at the rostrocaudal levels of the pontine nuclei. These obsenrations provide anatomic evidence of how this inhibitory neural element performs its function in the cortico-prontocerbellar circuitry.

• The Journal of Korean Medicine
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• v.23 no.3
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• pp.211-222
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• 2002

Currently convulsion is considered to be a chronic central nerve disease characterized by involuntary and severe muscle contraction or spasm. In many recent studies, convulsion's mechanism is due to unbalance between stimulation and suppression of the central nerve system, such as GABA and glutamic acid. Objectives : This study was performed to examine the anticonvulsant effects of Podam-hwan on brain GABA levels and glutamate content in picrotoxin-induced convulsions and to determine the inhibitory activity on GABA transaminase. Methods : Brain GABA levels and glutamate content in the brains of picrotoxin-induced mice using reverse phase HPLC method, anticonvulsant effect in vivo, and the inhibitory effect on GABA transaminase activity in vivo have been investigated. Results : Podam-hwan significantly lengthened the onset time of picrotoxin-induced convulsion at a concentration of 15mg/kg, but did not show a dose-dependent pattern. Also, Podam-hwan shortened the duration of convulsion by 52.2% at a dose of 30mg/kg in comparison with the control group. Podam-hwan inhibited dose-dependently GABA transaminase activity by 35.5% at 30mg/kg, comparing with the control gmup. Podam-hwan also increased the brain GABA level by 38.7% and 68.8% at doses 15mg/kg and 30mg/kg, respectively. In addition, Podam-hwan decreased the brain glutamate level by 9.6% and 17.8% at doses 15mg/kg and 30mg/kg, respectively. Conclusions : Podam-hwan can be prescribed for the treatment of convulsion by enhancement of brain GABA level and inhibition of GABA transaminase activity.

• 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.

• 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.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.104-109
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• 2007

Lactic acid bacteria that accumulated ${\gamma}-aminobutyric$ acid (GABA) in culture medium were screened to identify strains with high GAB A-producing ability. One strain, MS, which was isolated from kimchi, showed the highest GABA-producing ability among the screened strains. MS was identified as Lactobacillus buchneri based on Gram-staining, metabolic characteristics, and 16S rDNA sequence determination, Optimum culture conditions for GABA production were determined: MRS broth containing 5% MSG, 1% NaCl, and 1% glucose, at an initial pH of 5.0, the incubation temperature at $30^{\circ}C$ for 36 h. Under these conditions, MS produced GABA at a concentration of 251 mM with a 94% GABA conversion rate. Moreover, culture extracts of Lb. buchneri MS partially or completely protected neuronal cells against neurotoxicantinduced cell death.

• The Korean Journal of Pain
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• v.20 no.2
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• pp.106-110
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• 2007

Background: A phosphodiesterase 5 inhibitor, sildenafil, has been effective against nociception. Several lines of evidence have demonstrated the role of the GABAergic pathway in the modulation of nociception. The impact of the GABA receptors on sildenafil was studied using the formalin test at the spinal level. Methods: Male SD rats were prepared for intrathecal catheterization. The formalin test was induced by subcutaneous injection of formalin solution. The change in the activity of sildenafil was examined after pre-treatment with GABA receptor antagonists ($GABA_A$ receptor antagonist, bicuculline; $GABA_B$ receptor antagonist, saclofen). Results: Intrathecal sildenafil dose-dependently attenuated the flinching observed during phase 1 and 2 in the formalin test. The antinociceptive effect of sildenafil was reversed by the $GABA_B$ receptor antagonist (saclofen) but not by the $GABA_A$ receptor antagonist (bicuculline) in both phases. Conclusions: Intrathecal sildenafil suppressed acute pain and the facilitated pain state. The antinociception of sildenafil is mediated via the $GABA_B$ receptor, but not the $GABA_A$ receptor, at the spinal level.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.1
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• pp.50-60
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• 2021

Objective: This study investigated the mRNA expression of gamma-aminobutyric acid (GABA) receptors in the sperm of oligoasthenoteratozoospermic (OAT) and teratozoospermic (TER) men compared to normozoospermic (NOR) men, as well as the relationships between GABA receptor expression and sperm parameters, fertilization rate, and embryo quality. Methods: The mRNA expression of GABA A-α1 and GABA B-R2 receptors in sperm was examined using reverse transcription-polymerase chain reaction in three groups of patients: NOR (n=32), OAT (n=22), and TER (n=45). The fertilization rate and embryo quality were assessed in 35 patients undergoing intracytoplasmic sperm injection (ICSI; 10 NOR, 10 OAT, and 15 TER men). Results: OAT men had significantly higher mRNA expression of GABA A-α1 and GABA B-R2 receptors in sperm than NOR men; however, the difference between TER and NOR men was not significant. High levels of these receptors were significantly correlated with low sperm concentration, motility, and morphology, as well as the rate of good-quality embryos (GQEs) at the cleavage stage after ICSI. Patients whose female partners had a >50% GQE rate at the cleavage stage had significantly lower levels of GABA A-α1 receptor expression than those whose partners had a ≤50% GQE rate. Conclusion: Our findings indicate that mRNA levels of GABA receptors in human sperm are correlated with poor sperm quality and associated with embryo development after ICSI treatment. The GABA A-α1 receptor in sperm has a stronger relationship with embryo quality at the cleavage stage than the GABA B-R2 receptor.

• Journal of Yeungnam Medical Science
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• v.11 no.2
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• pp.314-322
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• 1994

This study aimed to investigate the existence of GABA receptor and the mechanisms of action of GABA and diazepam on the trachealis muscle isolated from dog. Horizontal muscle strips of $2mm{\times}15mm$ were prepared from canine trachea, and isometric myography in isolated muscle chamber bubbled with 95/5%-$O_2/CO_2$at $36^{\circ}C$, at the pH of 7.4 was performed. Muscle strips contracted responding to the electrical field stimulation (ESP) by 2~20 Hz, 20 msec, monophasic square wave of 60 VDC GABA and diazepam suppressed the EFS-induced contractions to the similar extent, significantly. (p<0.05) Bicuculline, a $GABA_A$ receptor antagonist blocked both GABA- and diazepam- inhibitions; but DAVA, a $GABA_B$ receptor antagonist did not affect either of them. These results suggest that in the canine trachealis muscle, there may be only $GABA_A$ receptor, and GABA and diazepam inhibit the contractility via $GABA_A$A receptor.

• KSBB Journal
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• v.27 no.2
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• pp.127-130
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• 2012

In this study, the effects of pH, temperature, IPTG concentration and substrate (MSG) concentration on gamma-aminobutyric acid (GABA) production in engineered Escherichia coli were investigated. Glutamate decarboxylase and glutamate/GABA antiporter were overexpressed in GABA aminotransferase knock-out strain for GABA production. The result of optimization study showed the GABA bioconversion was optimized at pH 3.5, $30^{\circ}C$, 0.5 mM IPTG, 10 g/L MSG. At this condition, 5.23 g/L of final GABA concentration of was achieved from 10 g/L of MSG, which corresponded to a GABA yield of 85.77%.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.783-791
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• 2022

Gamma-aminobutyric acid (GABA) improves various physiological illnesses, including diabetes, hypertension, depression, memory lapse, and insomnia in humans. Therefore, interest in the commercial production of GABA is steadily increasing. Lactic acid bacteria (LAB) have widely been reported as a GABA producer and are safe for human consumption. In this study, GABA-producing LAB were preliminarily identified and quantified via GABase assay. The acid and bile tolerance of the L. plantarum FBT215 strain were evaluated. The one-factor-at-a-time (OFAT) strategy was applied to determine the optimal conditions for GABA production using HPLC. Response surface methodology (RSM) with Box-Behnken design was used to predict the optimum GABA production. The strain FBT215 was shown to be acid and bile tolerant. The optimization of GABA production via the OFAT strategy resulted in an average GABA concentration of 1688.65 ± 14.29 ㎍/ml, while it was 1812.16 ± 23.16 ㎍/ml when RSM was applied. In conclusion, this study provides the optimum culture conditions for GABA production by the strain FBT215 and indicates that L. plantarum FBT215 is potentially promising for commercial functional probiotics with health claims.