• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.185-185
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• 2003

In-vitro expanded CNS precursors provide a potentially unlimited source of dopamine (DA) neurons for the experimental treatment in Parkinson's disease. An efficient dopaminergic differentiation from CNS precursors in vitro is limited to mesencephalic precursors isolated from early embryonic ages (embryonic day 11.5 (E11.5)-E12.5).(omitted)

• Toxicological Research
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• v.6 no.1
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• pp.99-107
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• 1990

Dopamine beta-hydroxylase (DBH) is a neurotransmitter biosynthetic enzyme which catalyzes the conversion of dopamine to norepinephrine. Although structural studies of the mature form of this enzyme have been extensive, the culmination of these finding had been hightly controversial and contradictory. In this study, biochemical approaches were taken to characterize the structure of mature DBH. Soluble bovine DBH was purified from aderenal medulla. Three bands of 69 kDa, 72 kDa and 75 kDa which were physically separable and similar in structure were observed by SDS-PAGE. Furthermore, gas phase sequence analysis revealed that the 72 kDa band consists of two polypeptides which are present at equimolar concentrations and differed in that one had three extra amino acids at the N-terminus. Taken together, the soluble form of DBH exist in at least four forms, three identified by SDS-PAGE, one of which consists of two polypeptides as identified by N-terminal sequence analysis. The significance of these forms and their possible biosynthetic mechanisms are discussed.

• Toxicological Research
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• v.3 no.1
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• pp.9-14
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• 1987

The effects of monosodium glutamate (MSG) on the activities if tyrosine hydroxylase (TH), dopamine ${\beta}$-hydroxylase (DBH), tryptophan hydroxylase (TPH) and monoamine oxidase (MAO) in various regions (cerebral cortex, striatum, midbrain, pons and medulla of nat brain have been determined. It was observed that up to 1mM MSGhad no significant effects on the activities of brain tyrosine hydroxylase, dopamine ${\beta}$-hydroxylase, tryptophan hydroxylase and monoamine oxidase in all regions of rat brain. These results indicated that MSG itself exerted no direct effect on the important enzymes synthsizing and metabolizing the monoaminergic neuronal system.

• Natural Product Sciences
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• v.10 no.3
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• pp.104-108
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• 2004

Five lignans including gomisin N (1), wuweizisu C (2), gomisin L1 (3), (+)-deoxyschizandrin (4), and gomisin J (5) have been isolated from the fruits of Schizandra chinensis. The structures of the isolated compounds were elucidated by analyzing MS and NMR spectra. Effects of the compounds isolated in this study on the dopamine content in PC12 cells were investigated to evaluate their inhibitory effectiveness. The gomisin N, wuweizisu C, and gomisin J showed 25.4%, 39.8%, and 35.1 %, respectively, inhibition effect on dopamine content in PC12 cells at the concentration of $50\;{\mu}g/ml$.

• Biomolecules & Therapeutics
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• v.6 no.1
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• pp.25-30
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• 1998

The roles of dopamine(DA) and N-methyl-D-aspartate(NMDA) system in the development and expression of morphine dependence were investigated by monitoring the concentrations of extracellular DA and its metabolites by in vivo microdialysis and simultaneous observation of behavioral changes in morphine dependent rats. Extracellular DA level in caudate putamen of morphine-dependent rat was decreased and the concentrations of its metabolites, dihydroxy phenylacetic acid(DOPAC) and homovanillic acid(HVA), were increased during naloxone-precipitated withdrawal. DA contents were recovered to normal levels by pretreatment of MK-801, a noncompetitive NMDA receptor antagonist, which may explain the mechanism of diminishing effect of MK-801 on withdrawal symptoms in morphine-dependent rats. MK-801(0.3 mg/tg, i.p.) induced the untoward hamful neurological signs such as ataxia and severe rotations, which may be produced by hyperactivation of dopaminergic system. These results suggest that MK-801 may inhibit the expression of mophine dependence by altering the dopamine release.

• Environmental Analysis Health and Toxicology
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• v.7 no.1_2
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• pp.59-65
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• 1992

The role of central dopaminergic neural activity for the maintenance of hypertension was tested. Two groups of animals were prepared; 1) Spontaneously hypertensive rats (SHR) at 14 weeks of age which reveal hypertension and 2) age-matched normotensive Wistar Kyoto rats (WKY). Blood pressures and dopamine turnover rate were measured from animals in each group. Dopamine turnover rate was determined in four brain regions such as telence-phalon, hypothalamus/thalamus, midbrain and pons/medulla, from concentration of dopamine at time zero, 1 and 2 hours after alpha-methyl-para-tyrosine (AMPT) was injected into animals. In SHR dopamine turnover rate was greater than normotensive rats in only midbrain. The result from the present study implicates that dopaminergic neural activity in midbrain may be positively coupled to the manifestation of hypertension in SHR.

• Archives of Pharmacal Research
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• v.14 no.2
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• pp.172-175
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• 1991

Abnormality in the central noradrenergic system may be related to the seizure prone state in the genetically epilepsy prone rats (GEPR). The present work deals with the characterization of the deficit in noradrenergic system if susceptitibility and intensity of seizure are dependent on central noradrenregic activities by comparing the activities of dopamine $\beta$-hydroxylase (DBH) which hydroxylates dopamine into noradrenaline. DBH activities were measured in 5 areas of brain of normal rats, native GEPR and severe GEPR. The results suggest that lower DBH activities in the midbrain of GEPRs may positively be coupled to the susceptibility to seizure, whereas the same characteristics of the native or severe GEPR are not neccessarily in parallel with the intensity of seizure.

• Sleep Medicine and Psychophysiology
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• v.25 no.1
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• pp.5-8
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• 2018

Restless legs syndrome (RLS) is a sleep disorder characterized by an urge to move the legs or arms and uncomfortable paresthesia in the legs. Treatment of RLS can be various depending on the causes, severity, and frequency of the symptoms. In the case of secondary RLS, it is important to identify and manage the cause of RLS. Dopamine agonists have been used as firstline treatments for primary RLS treatment. However, due to augmentation, which is a common side effect of dopamine agonists, recent treatment guidelines are changing to prefer to anticonvulsants such as pregabalin and gabapentin. Iron, opioid, or benzodiazepine may be used when anticonvulsants or dopamine agonists are not adequately treated. Because RLS is a chronic disease, it is essential to establish a long-term treatment plan considering both efficacy and side effects.

• The Korean Journal of Nuclear Medicine
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• v.34 no.3
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• pp.159-168
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• 2000

In the 1980s, techniques to image the human subjects in a three-dimensional direction were developed. Two major techniques are SPECT (Single Photon Emission Computed Tomography) and PET (Positron Emission Tomography) which allow the detector to detect a single photon or annihilation photons emitted from the subjects injected with radiopharmaceuticals. Since the latter two techniques can measure the density of receptors, enzymes and transporters in living human, it may be very important project to develop selective methods of labeling with radionuclides and to develop new radiopharmaceuticals. There has been a considerable interest in developing new compounds which specifically bind to dopamine and serotonin receptor and transporters, and it will be thus very useful to label those compounds with radionuclides in order to gain a better understanding in biochemical and pharmacological interactions in living human. This review mentions the characteristics of radioligands for the imaging of dopamine and serotonin receptors and transporters. Although significant progress has been achieved in the development of new PET and SPECT ligands for in vivo imaging of those receptors and transporters, there are continuous needs of new diagnostic radioligands.

• Korean Journal of Pharmacognosy
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• v.26 no.1
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• pp.62-65
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• 1995

Dopamine ${\beta}-hydroxylase$ (DBH) catalyses the enzymatic reaction of dopamine to norepinephrine. For the purpose of isolating DBH inhibitors from natural resources, thirty one kinds of medicinal plants were screened by tracing the inhibitory activities against bovine adrenal DBH, utilizing tyramine as a substrate. Among the crude drugs tested, leaves of Lactuca sativa L., Gardeniae Fructus, Magnoliae Flos and Scutellariae Radix showed potent enzyme inhibitory activities against DBH.