• 대한의생명과학회지
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• 제18권3호
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• pp.218-226
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• 2012

Dopamine is an enteric neurotransmitter that regulates gastrointestinal motility. This study was done to investigate whether dopamine modulates spontaneous pacemaker activity in cultured interstitial cells of Cajal (ICCs) from mouse using whole cell patch clamp technique, RT-PCR and live $Ca^{2+}$ imaging analysis. ICCs generate pacemaker inward currents at a holding potential of -70 mV and generate pacemaker potentials in current-clamp mode. Dopamine did not change the frequency and amplitude of pacemaker activity in small intestinal ICCs. On the contrary dopamine reduced the frequency and amplitude of pacemaker activity in large intestinal ICCs. RT-PCR analysis revealed that Dopamine2 and 4-receptors are expressed in c-Kit positive ICCs. Dopamine2 and 4 receptor agonists inhibited pacemaker activity in large intestinal ICCs mimicked those of dopamine. Domperidone, dopamine2 receptor antagonist, increased the frequency of pacemaker activity of large intestinal ICCs. In $Ca^{2+}$-imaging, dopamine inhibited spontaneous intracellular $Ca^{2+}$ oscillations of ICCs. These results suggest that dopamine can regulate gastrointestinal motility through modulating pacemaker activity of large intestinal ICCs and dopamine effects on ICCs are mediated by dopamine2 receptor and intracellular $Ca^{2+}$ modulation.

• 생물정신의학
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• 제2권1호
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• pp.57-62
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• 1995

항정신병 약물인 clozapine이 주로 작용하는 도파민 수용체로 알려진 도파민 $D_4$ 수용체는 각각 50 염기쌍에 해당하는 크기의 차이가 있음이 알려져 PCR을 이용해 정신분열증 환자와 정상대조군을 대상으로 도파민 $D_4$ 수용체 유전자의 대립형질 분포를 알아보았다. 정신분열증 환자군과 대조군 모두에 있어 여섯종류의 대립형질의 관찰되었으며 정신분열증 환자에서 네번 반복형태의 대립형질이 수적으로 더 많이 관찰되었지만 통계적으로 유의한 차이는 없었으며 정신분열증과 관련된 도파민 $D_4$ 수용체 유전자의 대립형질은 확인되지 않았다. 그러나 보다 객관적인 정보를 얻기 위해서 clozapine에 대한 반응에 따라 정신분열증 환자의 아형을 분류하고 그 아형에 따른 도파민 $D_4$ 수용체 유전자 대립형질분포의 차이에 관한검증이 필요하며, 나아가 도파민 $D_4$ 수용체 유전자의 발현에 있어 정신분열증 환자와 정상인에 차이가 있는지 여부를 밝히는 추적연구가 필요할 것으로 사료된다.

• Archives of Pharmacal Research
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• 제14권2호
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• pp.109-113
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• 1991

Two types of aggressive behavior were produced by selective breeding in ICR mimce. NC900 line mice exhibited high level of species-typical, isolation-induced aggression, conversely, NC100 line mice exhibited little aggression. The present study tested the hypothesis that these differences involved brain monoamine systems. Comparisons of microdissected samples from various brain regions showed that NC100 line mice had significantly lower concentrations of dopamine. DOPAC and HVA in the nucleus accumbens (NAB) and caudate nucleus (NCU) than NC900 line. Homogenate binding studies demonstrated that NC100 mice had significantly increased density of $D_1$ dopamine receptor, but not $D_2$ dopamine receptor in the caudate nucleus. These results support the hypothesis that central dopamine pathways play an important role in modulating the genetically selected differences in aggressive behavior, and of which intensity differs from TEX>$D_1$\;and\;$D_2$ dopamine receptors.

• 생물정신의학
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• 제9권1호
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• pp.15-24
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• 2002

Even though alcoholism is a multi-factorial psychiatric disorder, it is reasonable to suppose that genetic factors play a substantial role in the manifestation of this disorder. Because alcohol is the reinforcing substance which manifests its effects through activation of the mesolimbic dopaminergic reward pathway of the brain, the gene encoding dopamine receptor subtypes can be a major natural candidate gene. Since 1990, many association studies have identified strong evidence implicating the dopamine D2 receptor(DRD2) gene in alcoholism, specifically TaqI A minor(A1) allele. Association studies have also been conducted on other dopamine receptor(DRD3 & DRD4) polymorphisms but the results have yet to be confirmed. Through a number of other approaches, each dopamine receptor gene has been investigated in association with different phenotypes in alcoholism, but further researches will be needed. In conclusion, studies in the past decade have shown that the TaqI A1 allele of the DRD2 gene is associated with alcoholism in various subject groups. Other dopamine receptor genes have since been added to the list but yet to be identified. Thus, the knowledge of these genes and their functional significance will enhance the understanding of the underlying biological mechanisms of alcoholism. Furthermore, it could lead to more helpful prevention and treatment approaches to alcoholism.

• Biomolecules & Therapeutics
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• 제10권1호
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• pp.50-58
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• 2002

lt had been reproted previously that (${\pm}$)6-chloro-7,8-dihydroxy-1-phenyl 2,3,4,5-tetra-hydro -lH-3benzazepine (SKF 81297), dopamine $D_1$ receptor agonist, produced diuresis by both Indirect action through central function and direct action being induced in kidney. This study was attempted in order to examine the diuresis mechanism of such SKF 81297 Diuretic action of SKF 81297 given into the vein or the carotid artery was not affected by renal denervation, whereas diuretic action of SKF 81297 administered into a renal artery was blocked completely by renal denervation, and then diuretic action of SKF 81297 injected into carotid artery was inhibited by SCH 23390, dopamine $D_1$ receptor antagonist, given into carotid artery. Above results suggest that indirect diuretic action of SKF 81297 elicites through central dopamine $D_1$ receptor and direct diuresis in kidney by influence of renal nerves.

• Archives of Pharmacal Research
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• 제25권2호
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• pp.202-207
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• 2002

This study was performed to investigate the effect of tetrahydroisoxazolopyridine (THIP), a $GABA_A$ agonist, on the morphine-induced hyperactivity, reverse tolerance and postsynaptic dopamine receptor supersensitivity in mice. A single administration of morphine induced hyperactivity in mice. However, the morphine-induced hyperactivity was inhibited dose-dependently by the administration of THIP (0.2, 0.4 and 0.8 mg/kg, i.p.). In contrast, daily administration of morphine resulted in a reverse tolerance to the hyperactivity caused by morphine (10 mg/kg ,s.c.). THIP inhibited the development of reverse tolerance in the mice that had received the repeated same morphine (10 mg/kg s.c.) doses. The postsynaptic dopamine receptor supersensitivity, which was evidenced by the enhanced ambulatory activity its after the administration of apomorphine (2 mg/kg s.c.), also developed in the reverse tolerant mice. THIP also inhibited the development of the postsynaptic dopamine receptor supersensitivity indulged by the chronic morphine administration. These results suggest that the hyperactivity, reverse toterance and postsynaptic dopamine receptor supersensitivity induced by morphine can be inhibited activating the $GABA_A$ receptors.

• Journal of Gastric Cancer
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• 제6권3호
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• pp.132-138
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• 2006

목적: 도파민은 중추신경전달물질이지만 위장관에서 도파민수용체와 결합하여 점막상피세포 증식, 상피세포의 보호, 위암 세포증식과 관련이 있는 것으로 알려져 있다. 본 연구에서는 위암에서 기원한 세포주를 이용하여 도파민과 각각의 도파민 수용체가 위암 세포 증식과 억제에 작용하는 역할에 대해 알아보았다. 대상 및 방법: 위암세포기원에서 각각 유래한 세포주인 SNU601과 KCU-C2를 이용하여 RNA 추출 후 RT-PCR 시행 후 도파민수용체 D1, D2L과 D2S 각각에 대한 primer로 PCR을 시행하여 수용체 유전자의 상대적인 발현정도를 측정하였다. 도파민과 Dl 수용체의 대항제인 SCH 23390과 D2 수용체 대항제인 raclopride를 사용하여 약물처리에 따른 위암세포주에서 세포 증식에 대한 분석을 하였다. 결과: KCU-C2 세포주에서 D1과 D2L과 D2S 유전자 mRNA의 상대적인 발현정도는 모두 높은 발현을 보였지만, SNU 601 세포주에는 mRNA의 발현이 모두 낮은 수준이었으며, 특히 D2L mRNA는 발현되고 있지 않았다. 약물처리에 따른 위암세포주에서 세포증식에 대한 분석에서는 D1과 D2S 수용체를 통한 도파민의 신호는 세포의 증식을 억제하였고 D2L 수용체를 통한 도파민의 신호는 세포의 증식을 유도하였다. 결론: 본 연구를 통해 도파민이 위암의 세포증식과 억제에 관여하며, 도파민의 이러한 효과는 도파민의 신호가 어느 수용체를 통해 전달되었느냐에 따라 위암세포의 증식과 억제가 이루어짐을 알 수 있었다.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.270.1-270.1
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• 2002

The signaling pathway of D2 dopamine receptor was studied using yeaslt two-hybrid system.. The 3rd cytoplasmic loop of rat D2 dopamine receptor was used to screen the cDNA library of mouse brain. and ALY was found to interact with it. The interaction in the yeast was observed only with the 3rd cytoplasmic loop of D2 dopamine receptor but not with that of D3 or D4 dopamine receptor. The interaction between two proteins was also confirmed by GST pull-down assay. (omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.89.1-89.1
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• 2003

The signaling pathway of dopamine D$_2$ receptor was studied using yeast two-hybrid system. The 3rd cytoplasmic loop of rat D$_2$ receptor was fond to interact with ALY. The interaction in the yeast was observed only with the 3rd cytoplasmic loop of D$_2$ receptor but not with that of D$_3$ or D$_4$ dopamine receptor. The interaction between two proteins was also confirmed by GST pull-down assay. Co-expression of D$_2$ receptor and ALY enhanced the expression of Lef-1 promoter in C6 cells and the promoter of D$_2$ dopamine receptor itself.

• 생물정신의학
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• 제4권2호
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• pp.218-224
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• 1997

The results regarding an association between the polymorphism sites in the dopamine $D_1$ receptor gene and schizophrenia compelled us to study the distribution of the polymorphism in Korean schizophrenia and controls. Eighty-eight schizophrenic patients and normal controls were examined by case-control study for distribution of the polymorphism of the dopamine $D_1$ receptor gene in Korean popualtion to minimize the effect of racial differencies in gene frequencies. The frequencies of the $B_1$ and $B_2$ in schizophrenic patients were 0.11 and 9.89, respectively. And 0.10 and 0.90 in normal control. Ther was no significant differences in the frequencies in the allele $B_1$ and $B_2$between schizophrenic patients and normal controls. The author present here the evidence of a lack of alleic association between the polymorphism of the dopamine $D_1$ receptor gene and Korean schizophrenic patients. The assumption that the dopamine $D_1$ receptor gene has a genetic role in the development of schizophrenia was not suppoorted by this case-control study.