• Archives of Pharmacal Research
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• 제22권3호
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• pp.262-266
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• 1999

Dopamine transporter (DAT) plays the most important role in terminating the actions of dopamines released into the synaptic cleft. DAT is also the target of various psychotropic drugs such as cocaine and amphetamine. In this study were prepared DAT-specific antibodies using the 2nd extracellular loop of rat DAT as an antigen. The 2nd extracellular loop of the rat DAT was expressed in bacterial as a fusion protein with glutathione-S-transferase, and injected ito rabbits to raise antibodies. Produced antibodies clearly recognized the rat DAT in ELISA, immunoblotting, and immumoprecipitation. As expected from the high sequence homology between the rat and human DAT, the antibodies raised for the rat DAT cross-reacted with the human DAT in the immunoblotting. Considering the specificity for DAT with wide range of applications such as ELISA, immunoblotting, and immunoprecipitation, these antibodies would be valuable tool for understanding the pharmacological actions of dopamine transporter and drug addition.

• 약학회지
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• 제39권2호
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• pp.161-168
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• 1995

Brain dopamine systems play a central role in the control of movement, hormone release, and many complex behavior. The action of dopamine at its synapse is terminated predominately by high affinity reuptake into presynaptic terminals by dopamine transporter (DAT). The dopamine transporter(DAT) is membrane protein localized to dopamine-containing nerve terminals and closely related with cocaine abuse, Parkinsonism, and schizophrenia. In present study, the recombinant plasmid pRc/CMV-DAT, constructed by subcloning of a cDNA encoding a bovine DAT into eukaryotic expression vector pRc/CMV, was stably transfected into CV-1 cells(monkey kidney cell line). The DAT activities in the cell lines selected by Geneticin$^{R}$ were determined by measuring the uptake of $[^3H]$-dopamine. The transfected cell lines showed 30-50 fold higher activities than untransfected CV-1 cell line, and this result implies that DAT is well expressed and localized in transfected cells. The transfected cells accumulated $[^3H]$-dopamine in a dose-dependent manner with a $K_{m}$ of 991.6nM. Even though high doses of norepinephrine, epinephrine, serotonin, and choline neurotransmitters inhibited the uptake of $[^3H]$-dopamine, DAT in transfected cell line was proven to be much more specific to dopamine. The psychotropic drugs such as GBR12909, CFT, normifensine, clomipramine, desipramine, and imipramine inhibited significantly the dopamine uptake in tissue culture cells stably transfected with DAT cDNA. Radioactive in situ hybridization was done to map the cellular localization of DAT mRNA-containing cells in the adult rat central nervous system. The strong hybridization signals were detected only in the substantia nigra pars compacta and ventral tegmental area. The restricted anatomical localization of DAT mRNA-containing cells confirms the DAT as a presynaptic marker of dopamine-containing cells in the rat brain.

• 생물정신의학
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• 제9권1호
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• pp.8-14
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• 2002

Patients with attention deficit hyperactivity disorder(ADHD) have symptoms of inattention, hyperactivity, impulsivity. Symptoms of ADHD are responsive to medications such as methylphenidate, dextroamphetamine, pemoline, and bupropion. The functional change of the dopamine transporter is related to the therapeutic effect of these drugs. This can be one reason for the dopamine transporter to be emphasized in the research field of ADHD. ADHD has a genetic tendency. Since dopamine transporter gene(DAT1) knock out mice were reported to be several times more active than normal mice in a novel situation, lights has been shed on DAT1 as a candidate gene for ADHD. Though there have been several studies which reported an association between DAT1 and ADHD, the association between DAT1 and ADHD is not conclusive. Since Vandenbergh reported the DAT1 polymorphism with variable number of tandem repeats(VNTR), and the racial differences in allelic frequencies of the DAT1, wide ethnic variation in the distribution of the DAT1 polymorphism had been confirmed. Wide ethnic variation in the distribution of the DAT1 suggested that there might be ethnic difference in the association between DAT1 and ADHD. Before applying previous findings to Koreans, verification might be needed for Korean patients with ADHD.

• 생물정신의학
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• 제4권1호
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• pp.48-53
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• 1997

CV(bDAT) cell line, expressing dopamine transporter stably, has been established by transfection of CV-1 cells with bovine dopamine transporter cDNA. Using CV(bDAT) cells, the effects of various antipsychotic drugs on dopamine uptake activity were investigated. All of antipsychotic drugs tested, inhibited the [$^3H$]dopamine uptake into CV(bDAT) cells with $IC_{50}s$ in the low to mid micromolar range, implying that antipsychotic drugs may produce overflow of dopamine in the synaptic cleft of dopaminergic neuron.

• 대한핵의학회지
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• 제37권1호
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• pp.34-42
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• 2003

The dopamine transporter (DAT) is responsible for the re-uptake of dopamine from the synaptic cleft and is located on dopaminergic nerve terminals only. DAT single photon emission computed tomography (SPECT) and positron omission tomography (PET) imaging, therefore, offer the unique opportunity to study via striatal uptake the integrity of presynaptic dopaminergic nerve terminals in vivo. In recent years SPECT and PET using specific ligands binding to DAT have evolved as an useful tool for diagnosing and monitoring progression of neurodegenerative disorders affecting dopaminergic systems. This article briefly reviews the literature dealing with DAT SPECT and PET imaging in parkinsonism and other neurodegenerative disorders.

• 생물정신의학
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• 제25권1호
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• pp.16-20
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• 2018

Objectives Psychological resilience is the ability to cope with stress. The genetic background behind psychological resilience is not much known. The serotonin transporter and dopamine transporter are implicated in stress related psychology and emotional processing. The aim of this study is to investigate a possible genetic role of functional polymorphisms of serotonin and dopamine transporters for psychological resilience. Methods A total of 951 healthy adult subjects were included. Psychological resilience was measured using Connor-Davidson Resilience Scale (CD-RISC). Genotyping was performed for serotonin transporter gene(SERT) promoter variable number tandem repeat (VNTR) and dopamine transporter gene(DAT1) 3'-untranslated region (UTR) VNTR. Genetic association analysis was conducted between genotypes and the CD-RISC score. Results No genetic association was observed for SERT promoter VNTR or DAT1 3'-UTR VNTR with CD-RISC score. No genetic interaction between SERT promoter VNTR and DAT1 3'-UTR VNTR with CD-RISC score was detected. Conclusions Either serotonin or dopamine transporter did not seem to play a significant role for psychological resilience in this sample.

• 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.

• 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.

• 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.

• 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.