• Nuclear Medicine and Molecular Imaging
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• 제41권2호
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• pp.152-157
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• 2007

Imaging of the dopamine transporter (DAT) provides a marker for the integrity of presynaptic nigrostriatal dopaminergic system. DAT density is reduced in Parkinson disease, multiple system atrophy, and progressive supranuclear palsy. In patients with suspicious parkinsonism, normal DAT imaging suggests an alternative diagnosis such as essential tremor, vascular parkinsonism, or drug-induced parkinsonism. DAT imaging is a useful tool to aid clinician's differential diagnosis in parkinsonism.

• 생물정신의학
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• 제8권2호
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• pp.239-245
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• 2001

Objective : Dopamine transporter is member of family of Na/Cl dependent neurotransmitter transporter, 12 transmembrane domain, that has high substrate specificity, affinity. It is related with dopamine reuptake in presynaptic vesicle. DAT has a VNTR in its 3'-untranslated region(UTR). 3'-UTR VNTR polymorphism is related with modification of dopamine transmission. The association between with VNTR polymorphism and neuropsychiatric disorders such as alcohol dependence, and low activity ALDH has been studied, but their relationship is unclear. We study about association of 3'-UTR VNTR of DAT gene and G2319A and alcohol dependence. Method : Group of Korean subjects were studied with alcohol dependence(n=49 male) compared to mentally healthy controls(n=53 male). The peripheral blood sample was acquired, and Polymerase Chain Reaction(PCR) amplification, MspI procedure was done. Result : There was a significant difference between alcohol dependence group and normal control(genotype frequency p<0.05, allele frequency p<0.05) Allele A frequency and genotype(GG, GA) frequency was a significant difference between alcohol dependence group and normal control(p<0.05). Conclusion : Our study showed that genetic polymorphism of DAT1 G2319A had relation with alcohol dependence.

• 생물정신의학
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• 제11권2호
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• pp.165-172
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• 2004

Objective:Although polymorphism of dopamine transporter gene(DAT1) has been considered to be implicated in the pathogenesis of social phobia, previous investigations have been inconsistent and controversial. The authors investigated the relationship between DAT1 polymorphism and social phobia in Koreans. Methods:DAT1 and alleles of fifty subjects who met DSM-IV criterion of social phobia, and those of age- & sex- matched fifty normal controls in Korea were compared. Additionally, patients were grouped into generalized(33) and nongeneralized(17) types and DAT1 polymorphism was compared with that of age- & sex- matched controls. DAT1 with variable number of tandem repeats(VNTR) were determined by using polymerase chain reaction. To compare the distribution of the DAT1 polymorphism between different groups, Fisher's exact test was used. Results:There were no significant differences in either genotypic(p=0.451) or allelic(p=0.452) distributions between the social phobia patients and the controls. There also were no differences in genotypic distribution between subtypes of social phobia patients and the controls. Conclusion:We couldn't find any association between DAT1 polymorphism and social phobia. Further studies including larger number of samples and diverse clinical variables should be conducted to elucidate the present findings.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제12권2호
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• pp.179-191
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• 2001

연구목적：신생아의 행동 특성과 DAT1, DRD2, DRD3 및 DRD4 유전자 다형성 사이에 연관이 있는지 평가하였다. 방 법：2000년 4월 17일부터 2000년 6월 17일까지 출생한 정상 신생아 114명을 대상으로 하였다. 신생아 행동 평가는 Neonatal Behavioral Assessment Scale(NBAS)을 이용하여 생후 약 18시간에 평가하였으며, 출산시 제대혈액을 채취하여 DAT1, DRD2, DRD3 및 DRD4 유전자 다형성을 검사하였다. DAT1, DRD2, DRD3 및 DRD4 유전자의 유전자형에 따라서 집단 사이에 NBAS 7개 항목 점수를 비교하였다. 결 과：DAT1 유전자는 10/10 유전자형 집단과 비교해서 기타 유전자형 집단이 사회성-상호작용, 상태 조직력 및 상태 조절 능력 항목에서 유의하게 점수가 높았다. DRD2 유전자 Ser311/Cys311 유전자형은 Ser/Ser 유전자형 집단과 기타 유전자형 집단 사이에 NBAS 항목 점수에 유의한 차이가 없었다. DRD2 유전자는 TaqI A 및 TaqI B 유전자형에 의한 집단 사이에 NBAS 항목 점수에 유의한 차이가 없었다. DRD3 유전자는 유전자형에 의한 집단 사이에 NBAS 항목 점수에 유의한 차이가 없었다. DRD4 유전자 promoter 유전자형에 의한 집단 사이에 NBAS 항목 점수에 유의한 차이가 없었다. DRD4 유전자 반복배열이 긴 유전자형 집단은 짧은 유전자형 집단보다 습관화 항목 점수가 유의하게 높았다. 결 론：이러한 성적은 DAT1 및 DRD4 유전자 반복배열 다형성이 신생아 행동 특성에 영향을 미치는 유전적 기전일 가능성을 시사한다.

• 대한핵의학회지
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• 제36권4호
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• pp.224-231
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• 2002

목적: 정신분열병의 병태생리와 이미 임상적인 효과와 안전성이 확인된 비정형항정신병약물의 하나인 올란자핀의 작용기전 중 도파민전달체에 대한 효과를 구명하고자 본 연구를 고안했다. 대상 및 방법: 최소 4주 이상 항정신병약물을 사용하지 않았고 DSM-IV진단기준을 만족시키는 정신분열병 환자 6명(남 3, 여 3)에게 본 연구의 목적을 설명한 후 동의를 얻고 올란자핀 사용 전, 사용 4주 후 2회 $[^{123}I]-{\beta}-CIT$ SPECT영상을 얻었다. 얻은 영상에서 선조체/후두엽 비율을 측정했고 미상/피각으로 나누어 약물 사용 전 후를 비교분석 했다. 결과: 선조체 및 미상/피각 전부위의 $[^{123}I]-{\beta}-CIT$ 결합율은 올란자핀 사용 4주후 사용 전에 비해 의미있는 증가를 보였다(p<0.05). 결론: 본 연구결과는 올란자핀이 도파민전달계 중 도파민 운반체에 변화를 보임을 시사하고 있으나 확증을 위해서는 더 많은 환자와 정상인을 대상으로 한 비교 연구가 필요하다고 생각된다.

• 약학회지
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• 제43권6호
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• pp.743-750
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• 1999

Human and bovine dopamine transporters (DAT) demonstrate discrete functional differences in the dopamine (DA) transport and cocaine binding. The functional analyses on the chimeras of human and bovine DAT have revealed that the region from the $133^{rd}{\;}to{\;}186^{th}$ residue(encompassing the $3^{rd}$ trans-membrane domain (TM) is responsible for the substrate transport and cocaine binding. The present studies have been done to find out the specific amino acid(s) which is essential for the binding of cocaine to DAT by interchanging the amino acids in that region between human and bovine DAT. When isoleucine, the $152^{nd}$ residue of chimera B3 (bovine DAT sequence) was transformed back to valine, the human DAT residue at the identical position, the cocaine binding was remarkably recovered to 98% of the human DAT values. In addition, the cocaine binding of the human DAT was decreased by 57% by substituting isoleucine for valine at position 152. When isoleucine at position 152 of the chimera B3 was converted to the other amino acids to provide an possible molecular basis for the functional role of the $152^{nd}$ residue, only the conversion to alanine among acids tested significantly the cocaine by 34%, but these effect were not as much as those by the conversion to valine. In conclusion, valine at position 152 is a crucial amino acid for the interaction of cocaine to the DAT.

• Biomolecules & Therapeutics
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• 제31권1호
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• pp.108-115
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• 2023

Numerous psychotropic and addictive substances possess structural features similar to those of β-phenethylamine (β-PEA). In this study, we selected 29 β-PEA derivatives and determined their structure-activity relationship (SAR) to their ability to inhibit dopamine (DA) reuptake; conducted docking simulation for two selected compounds; and identified their potential functionals. The compounds were subdivided into arylethylamines, 2-(alkyl amino)-1-arylalkan-1-one derivatives and alkyl 2-phenyl-2-(piperidin-2-yl)acetate derivatives. An aromatic group, alkyl group, and alkylamine derivative were attached to the arylethylamine and 2-(alkyl amino)-1-arylalkan-1-one derivatives. The inhibitory effect of the compounds on dopamine reuptake increased in the order of the compounds substituted with phenyl, thiophenyl, and substituted phenyl groups in the aromatic position; compounds with longer alkyl groups and smaller ring-sized compounds at the alkylamine position showed stronger inhibitory activities. Docking simulation conducted for two compounds, 9 and 28, showed that the (S)-form of compound 9 was more stable than the (R)-form, with a good fit into the binding site covered by helices 1, 3, and 6 of human dopamine transporter (hDAT). In contrast, the (R, S)-configuration of compound 28 was more stable than that of other isomers and was firmly placed in the binding pocket of DAT bound to DA. DA-induced endocytosis of dopamine D₂ receptors was inhibited when they were co-expressed with DAT, which lowered extracellular DA levels, and uninhibited when they were pretreated with compound 9 or 28. In summary, this study revealed critical structural features responsible for the inhibition of DA reuptake and the functional role of DA reuptake inhibitors in regulating D₂ receptor function.

• Biomolecules & Therapeutics
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• 제29권4호
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• pp.392-398
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• 2021

In this study, we determined the effect of 24 different synthetic 4-benzylpiperidine carboxamides on the reuptake of serotonin, norepinephrine, and dopamine (DA), and characterized their structure-activity relationship. The compounds with a two-carbon linker inhibited DA reuptake with much higher potency than those with a three-carbon linker. Among the aromatic ring substituents, biphenyl and diphenyl groups played a critical role in determining the selectivity of the 4-benzylpiperidine carboxamides toward the serotonin transporter (SERT) and dopamine transporter (DAT), respectively. Compounds with a 2-naphthyl ring were found to exhibit a higher degree of inhibition on the norepinephrine transporter (NET) and SERT than those with a 1-naphthyl ring. A docking simulation using a triple reuptake inhibitor 8k and a serotonin/norepinephrine reuptake inhibitor 7j showed that the regions spanning transmembrane domain (TM)1, TM3, and TM6 form the ligand binding pocket. The compound 8k bound tightly to the binding pocket of all three monoamine reuptake transporters; however, 7j showed poor docking with DAT. Co-expression of DAT with the dopamine D₂ receptor (D₂R) significantly inhibited DA-induced endocytosis of D₂R probably by reuptaking DA into the cells. Pretreatment of the cells with 8f, which is one of the compounds with good inhibitory activity on DAT, blocked DAT-induced inhibition of D₂R endocytosis. In summary, this study identified critical structural features contributing to the selectivity of a molecule for each of the monoamine transporters, critical residues on the compounds that bound to the transporters, and the functional role of a DA reuptake inhibitor in regulating D₂R function.

• 대한핵의학회지
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• 제32권1호
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• pp.10-19
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• 1998

The SPECT radiopharmaceuticals labeled with I-123 for dopamine transporter imaging have been used to measure dopamine transporters in patients with movement disorders. However, a cyclotron produced I-123 limits its availiability and ease of use as a radioisotope to be labeled with pharmaceuticals in routine clinical diagnostic procedures. Recently, new radiophannaceuticals for Tc-99m which has optimal characteristic for SPECT imaging have been developed to overcome the limits of using I-123. The purpose of this study was to compare the quality of [Tc-99m]TRODAT-1 with [I-123]IPT SPECT data and then to evaluate the usefulness of [Tc-99m]TRODAT-1 SPECT by using three noninvasive simplified quantitative methods. TRODAT-1 labeled with Tc-99m($15.93{\pm}0.82mCi$) and IPT labeled with I-123($6.60{\pm}0.11mCi$) were injected into five normal controls. Dynamic [Tc-99m]TRODAT-1 SPECT scans of brain were performed for 10 minutes each over 180 minnutes, and for 20 minutes at 4 hrs and 5 hrs. [I-123]IPT SPECT scans were performed for 5 minutes each over 120 minutes. Time activity curves were generated for the left basal ganglia(LBG), right basal ganglia(RBG), and occipital cortex(OCC). Dopamine transporter parameters were ohtained using (BG-OCC)/OCC, graphical method($R_V$), and area ratio method($R_A$). TRODAT-1 and IPT SPECT imaging showed high uptake at the level of the basal ganglia. (BG-OCC)/OCC ratios for TRODAT-1 and IPT were $0.80{\pm}0.14$, and $3.22{\pm}0.81$, $R_Vs$ were $0.62{\pm}0.12$, and $2.30{\pm}0.35$, and $R_As$ were $0.37{\pm}0.08$ and $1.73{\pm}0.31$, respectively. In conclusion, further improvement of [Tc-99m]TRODAT-1 imaging characteristics may be required to estimate the dopamine transporter concentrations in human brains although it shows clear BG localization.

• 수면정신생리
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• 제15권1호
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• pp.39-43
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• 2008

목 적 : 하지불안증후군(restless legs syndrome ; RLS)의 병인은 아직 불명확하지만, 도파민 결핍과 유전적 소인이 흔히 제기된다. RLS는 도파민수용체를 차단하는 항정신 병약물을 복용하는 환자들에서 더 흔히 발생하는 것으로 보인다. 본 연구에서는 정신분열병환자에서 항정신병약물에 의해 유발된 RLS와 도파민 수송체(dopamine transporter gene ; DAT1) 유전자가 연관이 있는지 알아보고자 하였다. 방 법: International Restless Legs Syndrome Study Group의 진단기준으로 190명의 한국인 정신분열병 환자들을 대상으로 RLS에 대해서 평가하였다. 유전자형분석은 중합효소연쇄반응기법을 사용하여 DAT1 유전자의 40 염기쌍(basepair) variable number of tandem repeat(VNTR)에 대해서 시행되었다. 결 과 : 우리는 44명의 RLS군과 146명의 비RLS군으로 환자들을 분류하였다. 두 군간의 유전자형과 대립유전자 빈도의 차이를 분석한 결과 유의한 차이를 발견할 수 없었다. 결 론 : 이 연구는 DAT1 유전자의 40 bp VNTR 다형성이 항정신병약물로 유발된 RLS와 연관이 없다는 것을 시사한다. 이 결과를 확증하기 위해서는 향후 보다 대규모의 연합연구가 필요할 것이다.