Production of γ-amino Butyric Acid by Lactic Acid Bacteria in Skim Milk

Jin Young Cha(차진영),Young Rok Kim(김영록),Bo Ram Beck(백보람),Ji Hun Park(박지헌),Cher Won Hwang(황철원),Hyung Ki Do(도형기) 한국생명과학회 2018 생명과학회지 Vol.28 No.2

동해안 지역 수산발효식품과 수산물로부터 다양한 종류의 유산균들을 분리하여 감마아미노낙산(GABA) 활성을 위해 분석을 하였다. 박층크로마토그래피(TLC)를 이용하여 GABA를 생성하는 4개의 균주를 확보하였으며, 16S rRNA sequencing 분석 결과를 통해 FSFL0004, FSFL0005, FSFL0036 균주는 Lactobacillus (Lb.) brevis, 그리고 FGL0007은 Lactococcus (Lc.) lactis에 가장 유사한 것으로 확인하였다. Lb. brevis FSFL0004와 FSFL0005는 발효된 아귀로부터 분리되었고, Lb. brevis FSFL0036는 갈치 젓갈로부터 분리되었으며, Lc. lactis FGL0007 균주는 참가자미의 내장으로부터 분리되었다. 고속액체크로마토그래피(HPLC)를 사용한 정량분석결과를 보면, FSFL0004, FSFL0005, FSFL0036과 FGL0007에서 각각 10,754.37 μg/ml, 13,082.79 μg/ml, 12,290.19 μg/ml, 45.07 μg/ml의 GABA가 생성되었다. GABA가 풍부한 낙농제품의 발효 종균으로서 상용화 실험을 위해 1% MSG를 포함한 탈지방우유에 4개의 균주를 각각 접종하였다. TLC 결과를 보면 4개의 균주 모두가 GABA 생성을 보였다. HPLC 분석 결과를 보면, 4균주 중 Lc. lactis FGL0007이 가장 높은 GABA 생성(431.42 μg/ml)을 보였다. 본 연구의 내용은 GABA가 함유된 유제품 개발의 기반이 될 수 있을 것으로 생각한다. Lactic acid bacteria were isolated from a variety of fermented seafoods and sea creatures from the East Sea Rim, Korea and were screened for γ-amino butyric acid-producing (GABA) activity. Through a 16S rRNA sequence analysis, the bacteria of interest, which were GABA-positive on the thin-layer chromatography analysis, were recognized as three isolates of Lactobacillus (Lb.) brevis and one isolate of Lactococcus (Lc.) lactis. Lb. brevis FSFL0004 and FSFL0005 were isolated from fermented anglerfish and Lb. brevis FSFL0036 was derived from salted cutlass fish. The Lc. lactis strain FGL0007 was isolated from the gut of a brown sole flounder. According to HPLC analysis, the GABA contents produced by FSFL0004, FSFL0005, FSFL0036 and FGL0007 were equivalent to 10,754.37 μg/ml, 13,082.79 μg/ml, 12,290.19 μg/ml, and 45.07 μg/ml respectively in 1% monosodium glutamate-supplemented methionyltRNA synthetase (MRS) broth. The four strains were inoculated in skim milk with 1% monosodium glutamate to commercialize the strains as starter cultures for GABA-enriched dairy products, and TLC results displayed the production of γ-amino butyric acid by all four strains in the adaptation media. Lc. lactis FGL0007 demonstrated the greatest GABA production (431.42 μg/ml) by HPLC analysis. The GABA production by lactic acid bacteria strains in the skim milk demonstrated in the present study may be helpful for the production of GABA-enriched dairy products.

Immunocytochemical Localization of GABA Transporter-3 in the Guinea Pig Retina

이은진(Eun-Jin Lee),오수자(Su-Ja Oh),정진웅(Jin-Woong Chung),천명훈(Myung-Hoon Chun) 대한해부학회 2002 Anatomy & Cell Biology Vol.35 No.2

망막을 포함하는 중추신경계통에서 억제성 신경전달물질로 작용하고 있는 GABA의 분비와 흡수에 GABA 운송물질이 중요한 역할을 하며, 이 물질은 최소한 3개의 아형으로 구분되고 있다. 이중 GABA 운송물질-1은 주로 신경세포에, 그리고 GABA 운송물질-3은 일부의 신경세포에 분포하되 주로 부챗살아교세포에 존재하는 것으로 흰쥐 및 토끼 망막에서 보고 된 바 있다. 그러나 설치류에 속하면서 비교적 많은 수의 원뿔세포를 함유하고 있는 기니픽 망막에서는 보고된 바 없다. 이 연구에서는 기니픽 망막에서 GABA 운송물질-3를 동정하고 이를 함유한 세포의 신경생화학적 특성을 GABA 운송물 질-3, GABA 합성효소 65, 및 CD15 항체를 이용한 면역세포화학법으로 관찰하였다. GABA 운송물질-3 면역반응은 속핵층에 위치한 일부의 무축삭세포체에서 관찰되었고, 이들 세포의 돌기는 신경절세포 층 가까이의 속얼기층에서 밀집하여 분포하였다. 모든 GABA 운송물질-3 표지세포는 GABA 합성효소65에 면역반응을 나 타내었다. 또한, GABA 운송물질-3 표지 무축삭세포 중 67%는 CD15 면역반응을 나타내었다. 이상의 결과에서 기니픽 망막에서 GABA 운송물질-3는 속얼기층에서 A17 무축삭세포를 통해 암전도로를 조절할 것으 로 생각된다. The cellular localization of the GABA transporter-3 (GAT-3) was examined in the guinea pig retina by immunocytochemistry, using antisera against GAT-3. GAT-3 immunoreactivity was localized to cell bodies in the inner nuclear layer, and labeled processes were densely distributed in the inner plexiform layer (IPL) close to the ganglion cell layer. All GAT-3 labeled cells exhibited GAD65 immunoreactivity. In addition, 67% of GAT-3 labeled amacrine cells showed carbohydrate epitope CD15 immunoreactivity. These results indicate that GAT-3 is involved in modulating the rod pathway in the IPL of the guinea pig retina via presumptive A17 amacrine cells.

Mono sodium glutamate (MSG) 발효 GABA의 수면유도 효과

김승섭(Seung-Seop Kim),오성호(Sung-Ho Oh),정명훈(Myoung-Hoon Jeong),조석철(Seok-Cheol Cho),국무창(Moo-Chang Kook),이석호(Seok-Ho Lee),변유량(Yu-Ryang Pyun),이현용(Hyeon-Yong Lee) 한국식품과학회 2010 한국식품과학회지 Vol.42 No.2

미배아 발효로부터 얻은 GABA 시료를 이용하여 양성대조군으로 사용된 우유와 doxylamine succinate, 음성대조군으로 사용된 caffeine, 일반대조군으로 사용된 증류수와 함께 실험군인 GABA 시료를 농도별로 투여하여 실험을 수행하였다. 멜라토닌 함량을 측정한 결과, 대조군의 2.607±0.410 pg/㎖에 비해 GABA 60 ㎎/㎖ 투여군은 3.243±0.154 pg/㎖, GABA 120 ㎎/㎖ 투여군은 3.425±0.182 pg/㎖, 우유에 녹인 GABA 120 ㎎/㎖ 투여군은 3.464±0.205 pg/㎖으로 나타났다. 반면에 GABA 시료의 섭취 기간에 따른 멜라토닌 호르몬의 누적효과는 유의성이 없었다. 세로토닌 함량을 측정한 결과 대조군의 4.73±0.67 ng/mL에 비해 GABA 60 ㎎/㎖ 투여군은 4.71±1.22 ng/㎖, GABA 120 ㎎/㎖ 투여군은 5.37±0.96 ng/㎖, 우유에 녹인 GABA 120 ㎎/㎖ 투여군은 6.34±0.59 pg/㎖으로 대조군의 평균값과 같거나 비교적 높은경향을 보였으며 농도별로 유의성이 있음을 확인하였다. 특히, GABA 120 ㎎/㎖ 투여시 멜라토닌과 세로토닌 모두 시판되는 수면보조제보다 높은 것으로 나타났다. 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±0.182 pg/㎖ and 5.37±0.963 ng/㎖, respectively, in response to feeding 120 ㎎/㎖ of GABA while they were 2.607±0.41 pg/㎖ 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 ㎎/㎖ 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.

보리 잎과 옥수수 수염의 혼합과 유산균 발효를 이용한 γ-aminobutyric acid 생산 증진

김형주,윤영걸 한국유기농업학회 2017 韓國有機農業學會誌 Vol.25 No.1

GABA는 glutamic acid decarboxylase에 의해서 L-glutamic acid가 탈탄산화되어 생합성된 비단백질 아미노산이다. GABA는 식물에서 스트레스에 대항한 대응반응으로 생성된다. 사 람의 중추신경계에서는 주요 억제성 신경전달물질 중 하나로 항고혈압, 항당뇨 효능이 있 다고 알려져 있다. 본 연구에서 우리는 보리 잎과 옥수수 수염을 유산균과 함께 발효함으 로써 GABA 생성을 증진시키고자 하였다. 보리 잎과 옥수수 수염을 다양한 무게 비율로 조 합하여 혼합하였고, 30℃에서 48시간 동안 배양기 안에서 L. plantarium과 함께 발효시켰다. 발효된 혼합물을 열수 추출한 후, thin layer chromatography와 GABase assay를 이용하여 GABA의 생산을 분석하였다. 우리는 9:1 혼합발효추출물이 다른 비율의 추출물 보다 GABA 함량이 높은 것을 확인하였는데 이것은 혼합과 발효기술이 보리 잎과 옥수수 수염 내 GABA 양 증진에 효과가 있음을 의미한다. 또한 몇 가지 생리활성을 분석한 결과 혼합 발효추출물의 항산화 효능이 비발효 추출물에 비하여 증진되었고 세포독성은 나타나지 않 음을 확인하였다. 이러한 결과는 보리 잎과 옥수수 수염의 조합과 이것을 유산균과 함께 발효시키는 방법이 고함량의 GABA와 증진된 생리 활성을 지닌 기능성 식품으로서의 개발 가능성이 있음을 의미한다. γ-aminobutyric acid (GABA) is a non-proteinogenic amino acid biosynthesized through decarboxylation of L-glutamic acid by glutamic acid decarboxylase. GABA is believed to play a role in defense against stress in plants. In humans, it is known as one of the major inhibitory neurotransmitters in the central nervous system, exerting anti-hypertensive and anti-diabetic effects. In this report, we wanted to enhance the GABA production from the barley leaf and corn silk by culturing them with lactic acid bacteria (LAB). The barley leaf and corn silk were mixed with various weight combinations and were fermented with Lactobacillus plantarum in an incubator at 30℃ for 48 h. After extracting the fermented mixture with hot water, we evaluated the GABA production by thin layer chromatography and GABase assay. We found that the fermented mixture of the barley leaf and corn silk in a nine to one ratio contained a higher level of GABA than other ratios, meaning that the intermixture and fermentation technique was effective in increasing the GABA content. We also tested several biological activities of the fermented extracts and found that the extracts of the fermented mixture showed improved antioxidant activities than the non-fermented extracts and no indication of cytotoxicity. These results suggest that our approach on combining the barley leaf and corn silk and its fermentation with LAB could lead to the possibility of the development of functional foods with high levels of GABA content and improved biological activities.

Naringenin modulates GABA mediated response in a sexdependent manner in substantia gelatinosa neurons of trigeminal subnucleus caudalis in immature mice

박선아,Nguyen Thao Thi Phuong,박수정,한성규 대한약리학회 2024 The Korean Journal of Physiology & Pharmacology Vol.28 No.1

The substantia gelatinosa (SG) within the trigeminal subnucleus caudalis (Vc) is recognized as a pivotal site of integrating and modulating afferent fiberscarrying orofacial nociceptive information. Although naringenin (4',5,7-thrihydroxy -flavanone), a natural bioflavonoid, has been proven to possess various biological effects in the central nervous system (CNS), the activity of naringenin at the orofacial nociceptive site has not been reported yet. In this study, we explored the influence of naringenin on GABA response in SG neurons of Vc using whole-cell patch-clamp technique. The application of GABA in a bath induced two forms of GABA responses: slow and fast. Naringenin enhanced both amplitude and area under curve (AUC) of GABA-mediated responses in 57% (12/21) of tested neurons while decreasing both parameters in 33% (7/21) of neurons. The enhancing or suppressing effect of narin -genin on GABA response have been observed, with enhancement occurring when the GABA response was slow, and suppression when it was fast. Furthermore, both the enhancement of slower GABA responses and the suppression of faster GABA responses by naringenin were concentration dependent. Interestingly, the nature of GABA response was also found to be sex-dependent. A majority of SG neurons from juvenile female mice exhibited slower GABA responses, whereas those from juvenile males predominantly displayed faster GABA responses. Taken together, this study indicates that naringenin plays a partial role in modulating orofacial nociception and may hold promise as a therapeutic target for treating orofacial pain, with effects that vary according to sex. he substantia gelatinosa (SG) within the trigeminal subnucleus caudalis (Vc) is recognized as a pivotal site of integrating and modulating afferent fiberscarrying orofacial nociceptive information. Although naringenin (4',5,7-thrihydroxy -flavanone), a natural bioflavonoid, has been proven to possess various biological effects in the central nervous system (CNS), the activity of naringenin at the orofacial nociceptive site has not been reported yet. In this study, we explored the influence of naringenin on GABA response in SG neurons of Vc using whole-cell patch-clamp technique. The application of GABA in a bath induced two forms of GABA responses: slow and fast. Naringenin enhanced both amplitude and area under curve (AUC) of GABA-mediated responses in 57% (12/21) of tested neurons while decreasing both parameters in 33% (7/21) of neurons. The enhancing or suppressing effect of narin -genin on GABA response have been observed, with enhancement occurring when the GABA response was slow, and suppression when it was fast. Furthermore, both the enhancement of slower GABA responses and the suppression of faster GABA responses by naringenin were concentration dependent. Interestingly, the nature of GABA response was also found to be sex-dependent. A majority of SG neurons from juvenile female mice exhibited slower GABA responses, whereas those from juvenile males predominantly displayed faster GABA responses. Taken together, this study indicates that naringenin plays a partial role in modulating orofacial nociception and may hold promise as a therapeutic target for treating orofacial pain, with effects that vary according to sex.

보리 잎과 옥수수 수염의 혼합과 유산균 발효를 이용한 γ-aminobutyric acid 생산 증진

김형주,윤영걸,Kim, Hyung-Joo,Yoon, Young-Geol 한국유기농업학회 2017 韓國有機農業學會誌 Vol.25 No.1

GABA는 glutamic acid decarboxylase에 의해서 L-glutamic acid가 탈탄산화되어 생합성된 비단백질 아미노산이다. GABA는 식물에서 스트레스에 대항한 대응반응으로 생성된다. 사람의 중추신경계에서는 주요 억제성 신경전달물질 중 하나로 항고혈압, 항당뇨 효능이 있다고 알려져 있다. 본 연구에서 우리는 보리 잎과 옥수수 수염을 유산균과 함께 발효함으로써 GABA 생성을 증진시키고자 하였다. 보리 잎과 옥수수 수염을 다양한 무게 비율로 조합하여 혼합하였고, $30^{\circ}C$에서 48시간 동안 배양기 안에서 L. plantarium과 함께 발효시켰다. 발효된 혼합물을 열수 추출한 후, thin layer chromatography와 GABase assay를 이용하여 GABA의 생산을 분석하였다. 우리는 9:1 혼합발효추출물이 다른 비율의 추출물 보다 GABA 함량이 높은 것을 확인하였는데 이것은 혼합과 발효기술이 보리 잎과 옥수수 수염 내 GABA 양 증진에 효과가 있음을 의미한다. 또한 몇 가지 생리활성을 분석한 결과 혼합발효추출물의 항산화 효능이 비발효 추출물에 비하여 증진되었고 세포독성은 나타나지 않음을 확인하였다. 이러한 결과는 보리 잎과 옥수수 수염의 조합과 이것을 유산균과 함께 발효시키는 방법이 고함량의 GABA와 증진된 생리 활성을 지닌 기능성 식품으로서의 개발 가능성이 있음을 의미한다. ${\gamma}$-aminobutyric acid (GABA) is a non-proteinogenic amino acid biosynthesized through decarboxylation of L-glutamic acid by glutamic acid decarboxylase. GABA is believed to play a role in defense against stress in plants. In humans, it is known as one of the major inhibitory neurotransmitters in the central nervous system, exerting anti-hypertensive and anti-diabetic effects. In this report, we wanted to enhance the GABA production from the barley leaf and corn silk by culturing them with lactic acid bacteria (LAB). The barley leaf and corn silk were mixed with various weight combinations and were fermented with Lactobacillus plantarum in an incubator at $30^{\circ}C$ for 48 h. After extracting the fermented mixture with hot water, we evaluated the GABA production by thin layer chromatography and GABase assay. We found that the fermented mixture of the barley leaf and corn silk in a nine to one ratio contained a higher level of GABA than other ratios, meaning that the intermixture and fermentation technique was effective in increasing the GABA content. We also tested several biological activities of the fermented extracts and found that the extracts of the fermented mixture showed improved antioxidant activities than the non-fermented extracts and no indication of cytotoxicity. These results suggest that our approach on combining the barley leaf and corn silk and its fermentation with LAB could lead to the possibility of the development of functional foods with high levels of GABA content and improved biological activities.

GABA를 담지한 자성 키토산 나노입자 제조와 약물의흡수 및 방출 연구

윤희수 ( Hee-soo Yoon ),강익중 ( Ik-joong Kang ) 한국화학공학회 2020 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.58 No.4

약물 전달 시스템(Drug Delivery System, DDS)은 인체에 발생한 질환을 치료를 할 때 약물을 효과적으로 투약하므로써 약물성분에 의한 부작용을 최소화하고, 약물의 효능을 최대한으로 크게하기 위해 기존의 알려진 성분의 약물이나 새로운 성분의 제형을 설계하여 환자의 약물치료 과정을 최적화하는 목적을 지향하는 기술로 정의된다. 본 연구에서는 Tripolyphosphate (TPP)의 농도가 키토산과의 가교결합을 통하여 제조되는 Chitosan nanoparticles (CNPs)의 크기에 미치는 영향을 측정하여 TPP의 농도가 낮을수록 작은 크기의 입자가 형성되는 것을 확인하였다. 그리고 산화철(Fe₃O₄)의 양에 따른 CNPs-Fe₃O₄의 특성을 측정하여 Fe₃O₄의 양이 많을수록 자성 약물 전달체로써의 특성이 잘 나타남을 확인하였다. 닌히드린 반응(Ninhydrin test)를 통하여 저농도 구간(0.004~0.02 wt%)에서는 Y = 0.00373 exp (179.729X) - 0.0114 (R² = 0.989), 고농도 구간(0.02~0.1wt%)에서는 Y = 21.680X - 0.290 (R² = 0.999) 의 γ-aminobutyric acid (GABA)의 농도에 따른 검량선을 얻었다. 이 검량선을 사용하여 흡수를 위하여 넣어주는 GABA의 양에 따른 최대 흡수율의 관계식 Y = -136.527 exp [(-90.0862)X] + 64.724 (R² = 0.997) 을 얻었으며, 초기에 넣어주는 GABA의 양이 약 0.04 g인 지점부터는 약 62.5%로 흡수율이 일정해 지고, 시간에 따른 GABA-Fe₃O₄-CNPs로부터 방출되는 GABA의 양을 측정하여 약 24 hr 이후부터 약물 방출이 종료되는 것을 확인하였다. 또한 최적의 조건에서 만들어진 GABA-Fe₃O₄-CNPs는 약 150 nm의 구형 입자이며, 그에 따른 입자의 특성이 잘 나타나는 것을 확인하여 약물 전달체로써 적합함을 알 수 있었다. The Drug Delivery System (DDS) is defined as a technology for designing existing or new drug formulations and optimizing drug treatment. DDS is designed to efficiently deliver drugs for the care of diseases, minimize the side effects of drug, and maximize drug efficacy. In this study, the optimization of tripolyphosphate (TPP) concentration on the size of Chitosan nanoparticles (CNPs) produced by crosslinking with chitosan was measured. In addition, the characteristics of Fe₃O₄-CNPs according to the amount of iron oxide (Fe₃O₄) were measured, and it was confirmed that the higher the amount of Fe₃O₄, the better the characteristics as a magnetic drug carrier were displayed. Through the ninhydrin reaction, a calibration curve was obtained according to the concentration of γ-aminobutyric acid (GABA) of Y = 0.00373exp (179.729X)-0.0114 (R² = 0.989) in the low concentration (0.004 to 0.02 wt%) and Y = 21.680X-0.290 (R² = 0.999) in the high concentration (0.02 to 0.1 wt%). Absorption was constant at about 62.5% above 0.04 g of initial GABA. In addition, the amount of GABA released from GABA-Fe₃O₄-CNPs over time was measured to confirm that drug release was terminated after about 24 hr. Finally, GABA-Fe₃O₄-CNPs performed under the optimal conditions were spherical particles of about 150 nm, and it was confirmed that the properties of the particles appear well, indicating that GABA-Fe₃O₄-CNPs were suitable as drug carriers.

흰쥐에서 반복적 스트레스가 GABA성 신경전달에 미치는 영향

김창수,이종범,성형모,시현석,김진성,박형배,정성덕,하정희 大韓神經精神醫學會 2000 신경정신의학 Vol.39 No.1

연구목적 : 일반적으로 생체는 각종 스트레스에 반응하여 적응(adaptation) 기전이 나타난다. 이러한 적응 기전과 관련하여 포유동물의 중요한 억제성 신경전달계인 GABA성 신경전달계의 스트레스성 자극에 대한 반응양상에 대한 연구가 진행되고 있다. 신경전달의 변화양상은 부하된 스트레스의 종류 및 기간에 따라 다양하게 나타나므로 더욱 상세한 연구를 필요로 한다. 방 법 : 본 연구에서는 하루 2시간의 부동화 스트레스를 반복적으로 2주간 부하한 흰쥐의 뇌조직에서 GABA성 신경전달의 변화 양상을 관찰하고자 하였다. 수용체 결합반응을 통하여 GABA 수용체의 각 component별 배위자들의 각 수용체에 대한 결합 반응의 변화 양상을 정상 대조군와 비교하여 보고, 유의한 변화가 있는 부분의 상세한 검정을 위하여 포화결합반응을 통하여 친화력(Kd) 및 최대결합력(Bmax)에서의 변화양상을 검색하였다. 뿐만 아니라 GABA성 신경전달에 관여하는 중요한 신경전달체인 내인성 GABA의 함량과 대사효소인 GABA transaminase의 활성도의 변화양상도 검색하였다. 결 과 : 연구결과 반복적인 부동화 스트레스는 GABA 수용체 효현제인 [³H]muscimol의 흰쥐 뇌조직 GABA 수용체에 대한 결합도에는 별다른 영향을 미치지 않았다. 대뇌피질조직의 GABA 대사효소인 GABA transaminase 활성도를 감소시켰으나, 피질조직외의 다른 조직의 GABA transaminase 활성도나 내인성 GABA의 농도에는 별다른 영향을 미치지 않았다. 반복적인 부동화 스트레스를 부하한 흰쥐의 대뇌피질, 해마 및 시상하부 조직에서는 [³H]flunitrazepam의 수용체 결합도가 감소하였으며, 포화결합 반응결과 수용체의 수가 감소하였음을 확인하였다. 결 론 : 이상의 결과를 요약하면, 흰쥐에게 부하한 반복적인 부동화 스트레스는 뇌조직의 benzodiazepine 수용체의 수를 감소시킴으로써 GABA성 신경전달을 감소시키며, 이러한 GABA성 신경전달계의 변환은 생체에서 스트레스로 인한 행동장애의 한 기전이 될 수 있을 것으로 생각되었다. Objectives : Changes of GABAergic neurotransmission in response to the application of different types of environmental stress have been the subject of research for over two decades. However, the nature of the changes induced by stress appear to show a dependent phenomena on the type and duration of stressor agent employed. Methods : For this reason, this study was performed to observe the effects of repeated stress on the radioligands binding to GABAA/benzodiazepine receptors of discrete brain regions. The author also examined the activity of GABA transaminase and the concentration of endogenous GABA. Male Sprague-Dawley rats, weighing 150-200g were forced to suffer an immobilization stress for 2 hours during 14 consecutive days. Results : Repeated immobilization stress decreased the binding of [3H]flunitrazepam on the benzodiazepine receptor in the cortex, hippocampus and hypothalamus. Saturation experiments followed by scatchard analyses of the results showed decreased density of benzodiazepine receptor and the affinity remained unchanged. Repeated immobilization stress did not affect the binding of [3H]muscimol on the GABAA receptor, the activity of GABA transaminase, and the concentration of endogenous GABA in the brain regions. Conclusions : From these results, it can be concluded that repeated immobilization stress modulated GABAergic neurotransmission via downregulation of the benzodiazepine receptor in the brain.

GABA_(A)α6 유전자 다형성에 따른 알코올 금단 증상의 발현 차이

한덕현,최정은,이병용,김영훈,김혜원,이혜경 大韓神經精神醫學會 2005 신경정신의학 Vol.44 No.2

Introduction : The gamma-aminobutyric acid type A (GABA_(A)) receptor is an important pharmacological target of alcohol.The phamacological characteristics of the receptor are largely determined by its subunit composition, Compared with all othera subtypes, the α 6- containing receptors are more sensitive to GABA and less sensitive to benzodiazepines. The purpose of thisstudy was to address a role for GABA_(A) α 6 receptor subunit gene in the development of alcohol dependence. The differentialmanifestation of alcohol withdrawal symptoms related to GABA_(A) α 6 polymorphism in patients treating with benzodiazepineswas also examined.Methods : Eighty-seven inpatients with alcohol dependence, and sixty healthy controls were evaluated using CIWA-Ar scale.Each patient was genotyped for GABA_(A) α 6 subunit. Association between GABA_(A) α 6 polymorphism and severity of Withd-rawal symptom were determined.Results : No significant difference was found in GABA_(A) α 6 receptor genetic type and allelic distribution between thealcohol dependent and control subject. Tremor was more severe in CC than TT type. TT type had higher degree of anxiety,agitation and headache than CC type. The GABA_(A) α 6 C allele increased the average score of tremor significantly, and T alleleincreased that of agitation.Conclusion : The results suggested that GABA_(A) α 6 genetic polymorphism was not associated with alcohol dependenceand with severity of alcohol withdrawal symptoms. But in benzodiazepine treated patients, GABA_(A) α 6 polymorphism andallelic type show the difference in severity of each withdrawal symptom. These differences of sevehty are partly responsiblefor the unique pharmacological properties associated with the GABA_(A) α 6 subunit.

GABA와 Benzodiazepine 수용체 및 그 기능

정영조,한기석 大韓神經精神醫學會 1991 신경정신의학 Vol.30 No.3

GABA is ubiquitously distributed throughout the CNS. It is probably the major central inhibitory aminoacid neurotransmitter which hyperpolarizes the postsynapic neurons and inhibits the release of neurotransmitters. Generally inhibition of GABA activity causes excitation leading to anxiety and convulsions, whereas activation of its activity causes antiexpressive. anticonvulsive activity and sedation. The GABA receptors have been divided into two distinct groups named GABA(A) and GABA(B) receptors by their pharmacological and physiological properties. GABA(A) receptors are coupled with Bz binding site and that in conjunction with a CI­ channel they form a supramolecular receptor complex which mediates rapid increasing of CI­ influx into postsynaptic neurons. thus contributing to the prompt inhibition of cellular excitability. On the contrary, the GABA(B) receptor does not contain an integral ion channel and is responsible for slow responses through receptor-G protein-effector complexes. GABA(B) receptors appear to be localized on presynaptic nerve terminals and stimulation of presynaptic GABA(B) receptors reduced Ca²+ influx, resulting in decreased release of neurotransmitters. Stimulation of presynaptic GABA(B) receptors increases K efflux, resulting in inhibition of cell firing. A division of function among the two types of GABA receptors appears to exist : GABA(A) receptor complex mediates anxiety, anticonvulsive activity and feeding, GABA(B) receptors, on the other hand, are involved in depression and analgesia. In those cases where GABA(A) and GABA(B) receptors mediate similar functions (e.g., cardiovascular regulation), they do so by affecting different transmitter systems and cellular mechanisms. The putative involvement of GABA(A) and GABA(B) receptors in various behavioral and physiological effects is summarized in Table 3. There are two types of Bz receptors in brain which are central and peripheral type Bz receptors. Central Bz receptors are in many regions of the brain, coupled with the receptors for GABA and they mediate the acute actions of Bz in CNS. Although there is general acceptance that Bz evert their major actions via the GABA(A) receptor, more recent studies suggest that other systems may be involved. In addition, endogenous anxiogenic ligands that interact with Bz receptors in several ways have been discovered, which of these,β-carbolines and DBI may produce anxiety and convulsion in human, The recent investigation of endogenous ligands and specific receptor agonist or antagonist and inverse agonist provide important new conceptual tools for the studies of anxiety and depression mechanisms. It is expected that a better understanding of GABA and Bz receptors will eventually help to demonstrate the biology of anxiety and depression.