• 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 Microbiology and Biotechnology
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• v.25 no.4
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• pp.464-468
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• 2015

The production of gamma-aminobutyric acid (GABA) using GABA-producing lactic acid bacteria (LAB) has been considered to be an attractive strategy. However, some LAB may produce biogenic amines (BA), which may be of concern from the safety viewpoint. The aim of the present study was to characterize the production of GABA and BA in the soybean pastes fermented by Aspergillus oryzae (A. oryzae) FMB S46471 and GABA-producing Lactobacillus brevis (L. brevis) GABA 100. After a ripening period of 90 days, the levels of BA (putrescine, cadaverine, histamine, and tyramine) and GABA in the fermented soybean were assessed by highperformance liquid chromatography. The soybean pastes fermented by A. oryzae and L. brevis showed a range of 7,130-11,592 mg/kg for GABA, 178-305 mg/kg for tyramine, 139-163 mg/kg for putrescine, 7.4-10.8 mg/kg for histamine, and 7.1-7.9 mg/kg for cadaverine, whereas the soybean pastes fermented by A. oryzae only showed a range of 30-1,671 mg/kg for GABA, 0.8-189 mg/kg for tyramine, 1.3-85 mg/kg for putrescine, up to 3.6 mg/kg for histamine, and 0.2-2.4 mg/kg for cadaverine. The results showed that the production of GABA was accompanied by the increase in the production of BA, even though the production levels of histamine and cadaverine were very low. This is the first study to simultaneously characterize the production of BA and GABA in GABA-enriched fermented soybean pastes, and warrants further study to minimize the production of BA while optimizing the production of GABA.

• Food Science of Animal Resources
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• v.34 no.4
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• pp.552-557
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• 2014

This study investigated the effects of ${\gamma}$-aminobutylic acid (GABA) on the quality and sensorial properties of both the GABA/NaCl complex and model meat products. GABA/NaCl complex was prepared by spray-drying, and the surface dimensions, morphology, rheology, and saltiness were characterized. For model meat products, pork patties were prepared by replacing NaCl with GABA. For characteristics of the complex, increasing GABA concentration increased the surface dimensions of the complex. However, GABA did not affect the rheological properties of solutions containing the complex. The addition of 2% GABA exhibited significantly higher saltiness than the control (no GABA treatment). In the case of pork patties, sensory testing indicated that the addition of GABA decreased the saltiness intensity. Both the intensity of juiciness and tenderness of patties containing GABA also scored lower than the control, based on the NaCl reduction. These results were consistent with the quality characteristics (cooking loss and texture profile analysis). Nevertheless, overall acceptability of the pork patties showed that up to 1.5%, patties containing GABA did not significantly differ from the control. Consequently, the results indicated that GABA has a potential application in meat products, but also manifested a deterioration of quality by the NaCl reduction, which warrants further exploration.

• International Journal of Oral Biology
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• v.33 no.4
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• pp.217-221
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• 2008

Bicuculline is one of the most commonly used $GABA_A$ receptor antagonists in electrophysiological research. Because of its poor water solubility, bicuculline quaternary ammonium salts such as bicuculline methiodide (BMI) and bicuculline methbromide are preferred. However, a number of studies have shown that BMI has non-$GABA_A$ receptor-mediated effects. The substantia gelatinosa (SG) of the trigeminal subnucleus caudalis (Vc) is implicated in the processing of nociceptive signaling. In this study, we investigated whether BMI has non-GABA receptor-mediated activity in Vc SG neurons using a whole cell patch clamp technique. SG neurons were depolarized by application of BMI ($20{\mu}M$) using a high $Cl^-$ pipette solution. GABA ($30-100{\mu}M$) also induced membrane depolarization of SG neuron. Although BMI is known to be a $GABA_A$ receptor antagonist, GABA-induced membrane depolarization was enhanced by co-application with BMI. However, free base bicuculline (fBIC) and picrotoxin (PTX), a $GABA_A$ and $GABA_C$ receptor antagonist, blocked the GABA-induced response. Furthermore, BMI-induced membrane depolarization persisted in the presence of PTX or an antagonist cocktail consisting of tetrodotoxin ($Na^+$ channel blocker), AP-5 (NMDA receptor antagonist), CNQX (non-NMDA receptor antagonist), and strychnine (glycine receptor antagonist). Thus BMI induces membrane depolarization by directly acting on postsynaptic Vc SG neurons in a manner which is independent of $GABA_A$ receptors. These results suggest that other unknown mechanisms may be involved in BMI-induced membrane depolarization.

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1664-1669
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• 2017

Gamma-aminobutyric acid is a precursor of nylon-4, which is a promising heat-resistant biopolymer. GABA can be produced from the decarboxylation of glutamate by glutamate decarboxylase. In this study, a synthetic scaffold complex strategy was employed involving the Neurospora crassa glutamate decarboxylase (GadB) and Escherichia coli GABA antiporter (GadC) to improve GABA production. To construct the complex, the SH3 domain was attached to the N. crassa GadB, and the SH3 ligand was attached to the N-terminus, middle, and C-terminus of E. coli GadC. In the C-terminus model, 5.8 g/l of GABA concentration was obtained from 10 g/l glutamate. When a competing pathway engineered strain was used, the final GABA concentration was further increased to 5.94 g/l, which corresponds to 97.5% of GABA yield. With the introduction of the scaffold complex, the GABA productivity increased by 2.9 folds during the initial culture period.

• Journal of Microbiology and Biotechnology
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• v.29 no.11
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• pp.1745-1748
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• 2019

Gamma-aminobutyric acid (GABA) plays important roles in host physiology. However, the effects of GABA are greatly restricted due to its low bioavailability in the human body. Here, a high acid-tolerance GABA-producing strain, Lactobacillus brevis Bmb5, was isolated from kimchi. Bmb5 converted glutamate to GABA (7.23 ± 0.68 ㎍/μl) at a rate of 72.3%. The expression of gadB gene, encoding the enzyme involved in the decarboxylation of glutamate to GABA, was decreased upon incubation. Our findings indicate GABA production in Bmb5 is not directly correlated with gadB gene expression, providing new insight into the mechanisms underlying GABA production in Lactobacillus.

• 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.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.1
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• pp.27-31
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• 2002

${\gamma}-Aminobutyric$ Acid (GABA) is contained in pancreatic islet ${\beta}-cells$ although its physiological role in pancreatic exocrine function is completely unknown at the present time. Recently, we have reported that exogenous GABA enhances secretagogue-evoked exocrine secretion in the isolated, perfused rat pancreas. This study was aimed to investigate an effect of exogenous GABA on pancreatic exocrine secretion in vivo evoked by intestinal stimulation. Rats were anesthetized with urethane (1.4 g/kg) after 24-h fast with free access to water. GABA $(10,\;30\;and\;100\;{\mu}mol/kg/h),$ given intravenously, did not change spontaneous pancreatic amylase secretion but dose-dependently elevated the amylase secretion evoked by intraduodenal sodium oleate (0.05 mmol/h). GABA $(30\;{\mu}mol/kg/h)$ also further increased the amylase secretion stimulated by CCK (30 pmol/kg/h) plus secretin (20 pmol/kg/h) but failed to modify the amylase secretion induced by secretin alone. GABA $(10,\;30\;and\;100\;{\mu}mol/kg/h)$ also dose-dependently elevated pancreatic amylase secretion evoked by CCK alone. Bicuculline $(100\;{\mu}mol/kg/h),$ a $GABA_A-receptor$ antagonist, markedly reduced the GABA-enhanced pancreatic responses to sodium oleate, CCK plus secretin or CCK alone. The results indicate that GABA enhances the sodium oleate-evoked pancreatic amylase secretion via $GABA_A-receptor$ in anesthetized rats, which may account for elevating the action of CCK released by sodium oleate.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.75-78
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• 2003

We analyzed the ${\gamma}$-aminobutyric acid (GABA) content of a selection of uncooked foods. Foods with GABA concentrations in excess of 100 nmole per g dry weight included: brown rice germ, brown rice sprouts, barley sprouts, bean sprouts, beans, corn, barley, brown rice, spinach, potatoes, sweet potatoes, yams, kale and chestnuts. Cereals included: brown rice germ, brown rice sprouts, barley sprouts, bean sprouts, beans, corn, barley, and brown rice and had GABA concentrations of 718, 389, 326, 302, 250, 199, 190, and 123 nmole per g dry weight (DW), respectively. The vegetables: spinach, potatoes, sweet potatoes, yams and kale contained 414, 166, 137, 129, 122 nmole GABA per g DW, respectively. The GABA concentration of chestnut was 188 nmole per g DW. However, oatmeal, adlay, broccoli, squash, carrots, onion, apples, lentinus edodes, green laver, and lactobacillus had GABA concentrations of less than 100 nmole per g DW. These results show that brown rice germ, sprouted cereals and spinach are good sources of plant-derived GABA. These data will be useful in selecting foods for the manufacturing of uncooked foods containing a relatively high concentrations of GABA.