• Journal of Korean Neurosurgical Society
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• 제67권5호
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• pp.510-520
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• 2024

Objective : Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases, characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta. The treatment of PD aims to alleviate motor symptoms by replacing the reduced endogenous dopamine. Currently, there are no disease-modifying agents for the treatment of PD. Zebrafish (Danio rerio) have emerged as an effective tool for new drug discovery and screening in the age of translational research. The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is known to cause a similar loss of dopaminergic neurons in the human midbrain, with corresponding Parkinsonian symptoms. L-type calcium channels (LTCCs) have been implicated in the generation of mitochondrial oxidative stress, which underlies the pathogenesis of PD. Therefore, we investigated the neuro-restorative effect of LTCC inhibition in an MPTP-induced zebrafish PD model and suggested a possible drug candidate that might modify the progression of PD. Methods : All experiments were conducted using a line of transgenic zebrafish, Tg(dat:EGFP), in which green fluorescent protein (GFP) is expressed in dopaminergic neurons. The experimental groups were exposed to 500 μmol MPTP from 1 to 3 days post fertilization (dpf). The drug candidates : levodopa 1 mmol, nifedipine 10 μmol, nimodipine 3.5 μmol, diethylstilbestrol 0.3 μmol, luteolin 100 μmol, and calcitriol 0.25 μmol were exposed from 3 to 5 dpf. Locomotor activity was assessed by automated tracking and dopaminergic neurons were visualized in vivo by confocal microscopy. Results : Levodopa, nimodipine, diethylstilbestrol, and calcitriol had significant positive effects on the restoration of motor behavior, which was damaged by MPTP. Nimodipine and calcitriol have significant positive effects on the restoration of dopaminergic neurons, which were reduced by MPTP. Through locomotor analysis and dopaminergic neuron quantification, we identified the neuro-restorative effects of nimodipine and calcitriol in zebrafish MPTP-induced PD model. Conclusion : The present study identified the neuro-restorative effects of nimodipine and calcitriol in an MPTP-induced zebrafish model of PD. They restored dopaminergic neurons which were damaged due to the effects of MPTP and normalized the locomotor activity. LTCCs have potential pathological roles in neurodevelopmental and neurodegenerative disorders. Zebrafish are highly amenable to high-throughput drug screening and might, therefore, be a useful tool to work towards the identification of disease-modifying treatment for PD. Further studies including zebrafish genetic models to elucidate the mechanism of action of the disease-modifying candidate by investigating Ca2+ influx and mitochondrial function in dopaminergic neurons, are needed to reveal the pathogenesis of PD and develop disease-modifying treatments for PD.

• 대한한의학회지
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• 제26권4호
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• pp.98-107
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• 2005

Objectives: Acupuncture treatment has been clinically used for functional recovery in Parkinson's disease. In the present study, we investigated the effect of acupuncture at Zusanli (ST36) on nigrostriatal dopaminergic neuronal cell death in rats. Methods: A Parkinson's disease model was induced by the unilateral injection of 6-hydroxydopamine (6-OHDA) into the striatum. Acupuncture treatment was performed at Zusanli (ST36) and at the hip, as a non-acupoint, once a day for 14 days. Two weeks after 6-0HDA injection, an apomorphine-induced rotational behavior test showed significant rotational asymmetry in rats with Parkinson's disease. Immunostaining for tyrosine hydroxylase demonstrated a dopaminergic neuronal loss in the substantia nigra and dopaminergic fiber loss in the striatum. Results: Acupuncture at the ST36 acupoint significantly inhibited rotational asymmetry in rats with Parkinson's disease, and also protected against 6-OHDA-induced nigrostriatal dopaminergic neuronal loss. These effects of acupuncture were not observed for non-acupoint acupuncture. Conclusions: The present study shows that acupuncture treatment, especially at the ST36 acupoint, can be used as a useful strategy for the treatment of Parkinson's disease.

• 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.267.2-267.2
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• 2002

MPP$\^$＋/ is known to be a neurotoxic substance that induces the degeneration of dopaminergic neurons and a Parkinsonism-like syndrome. MPP$\^$＋/ is retained intracellularly or accumulated in dopaminergic neurons via the dopamine-reuptake system. It inhibits mitochondrial electron transport in dopaminergic neurons. In addition. it generates hydroxyl radicals. which cause the peroxidation of membrane lipid or damage DNA. (omitted)

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2008년도 Proceedings of the Convention
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• pp.49-52
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• 2008

Parkinson's disease is characterized by motor disturbances and dopaminergic neurodegeneration. parkin and PINK1, two most critical Parkinson's disease-associated genes, have been intensively studied to address the underlying molecular pathogenesis of the disease, but our understanding still remains unclear. Through generation and characterization of Drosophila mutants for PINK1, we show that PINK1 is required for mitochondrial integrity and function in both indirect flight muscles and dopaminergic neurons. Surprisingly, we find that PINK1 mutants share striking phenotypic similarities with parkin mutants. Indeed, transgenic expression of parkin dramatically ameliorates all PINK1 loss-of-function phenotypes, but not vice versa, implicating that Parkin acts downstream of PINK1 in maintaining mitochondrial integrity and function in both muscles and dopaminergic neurons. With the establishment of the PINK1-Parkin pathway, we are trying to further investigate the detailed molecular relationship between PINK1 and Parkin using both mammalian dopaminergic neuronal cells for biochemical analysis and Drosophila model animal for genetic analysis. We believe that elucidating the molecular function of Parkinson's disease-associated genes will be of big help for the ultimate understanding of the pathogenic mechanism of this disease and also for the development of effective drugs for Parkinson's disease.

• 대한핵의학회지
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• 제19권2호
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• pp.69-79
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• 1985

To evaluate the effect of dopaminergic activity on aldosterone secretion, the plasma renin activity, serum cortisol and aldosterone were measured by radioimmunoassay in 6 normal controls and 12 patients who had hyponatremia and generalized edema or ascites with possible condition with secondary aldosteronism before and after(15, 30, and 60 min) 15 mg of metoclopramide by iv bolus injection and same method with 500 mg of L-dopa by per oral in 6 normal controls and 12 patients with edema ascites. The result were as follows; 1) The basal level of PRA was higher in patients rather than normal controls but PRA was not influenced by MC or L-dopa administration on both normal controls and patients group. 2) The serum cortisol level was significantly elevated at 30 min after MC injection compared with basal level in normal controls but no significant change was noted in patients group. After L-dopa administration the serum cortisol level was not changed in both normal controls and patients group. 3) The serum aldosterone level was significantly elevated in 15, 30 and 60 min after MC injection in normal controls, and there also same tendency of aldosterone secretion was noticed in patients group. On the other hands, there was no changes in aldosterone level in both normal controls and patients group with L-dopa administration. Above result means that MC stimulate aldosterone secretion by dopaminergic antagonist and aldosterone secretion in normal subject is controlled by maximal tonic dopaminergic inhibition. In edematous patients, however, both of the dopaminergic inhibitory and stimulating effect of PRA, ACTH etc on the aldosterone secretion seems to be variable.

• Natural Product Sciences
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• 제22권3호
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• pp.187-192
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• 2016

The goal of this study was to determine whether gypenosides (GPS) exert protective effects against dopaminergic neuronal cell death in a 6-hydroxydopamine (OHDA)-lesioned rat model of Parkinson's disease (PD) with or without long-term 3,4-dihydroxyphenylalanine (L-DOPA) treatment. Rats were injected with 6-OHDA in the substantia nigra to induce PD-like symptoms; 14 days after injection, groups of 6-OHDA-lesioned animals were treated for 21 days with GPS (25 or 50 mg/kg) and/or L-DOPA (20 mg/kg). Dopaminergic neuronal cell death was assessed by counting tyrosine hydroxylase (TH)-immunopositive cells in the substantia nigra and measuring levels of dopamine, norepinephrine, 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in the striatum. Dopaminergic neuronal cell death induced by 6-OHDA lesions was ameliorated by GPS treatment (50 mg/kg). L-DOPA treatment exacerbated 6-OHDA-induced dopaminergic neuronal cell death; however, these effects were partially reversed by GPS treatment (25 and 50 mg/kg). These results suggest that GPS treatment is protective against dopaminergic neuronal cell death in a 6-OHDA-lesioned rat model of PD with long-term L-DOPA treatment. Therefore, GPS may be useful as a phytotherapeutic agent for the treatment of PD.

• 한국안광학회지
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• 제5권2호
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• pp.15-20
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• 2000

성체 소의 망막에 존재하는 doparminergic 신경세포의 형태를 연구하였다. Dopaminerglc 세포는 항체면역세포화학적 방법을 이용하여 확인하였다. Tyrosine hydroxylase 면역 반응 신경 세포의 대부분은 내핵층의 가장 깊은 부분에 위치했다. 이들 세포들의 돌기들은 단층이었으며 그리고 내망상층의 1층내에 위치했다. Tyrosine-hydroxylase 면역 반응되는 두 번째 주요 세포 집단은 치환된 amacrine 세포들이다. 치환된 tyrosine-hydroxylase 면역 반응 amacrine 세포의 돌기들도 역시 내망상층의 1층내에 나타났다. 소수의 신경 세포의 돌기들은 외망상층에서 나타났다. 매우 낮은 밀도의 신경세포들은 내망상층의 중간과 깊은 층에서 tyrosine-hydroxylase 면역 반응 돌기들의 추가적인 층을 가졌다. Doparminergic 신경세포의 돌기들은 방사선형으로 넓게 신장되어 큰 모양을 형성하였고 수상돌기의 가지들은 적당하게 뻗어 있었다. 이러한 돌기들은 때때로 varicosity를 가지지만 "dendritic rings"을 형성하지는 않았다. 본연구의 결과는 doparminergic 세포는 소의 망막내 특이 신경세포 형태를 구성하는 것을 알 수 있었다.

• Journal of Acupuncture Research
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• 제32권1호
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• pp.23-36
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• 2015

Objectives : This study was designed to investigate the neuroprotective effects of Hominis-Placenta (HP)on dopaminergic neurons. Methods : We examined the effect of invitro administration of HP against 1-methyl-4-phenylpyridinium( MPP+)-induced dopaminergic cell loss in primary mesencephalic culture and also used behavioral tests and performed analysis in the striatum and the substantia nigra of mouse brain, to confirm the effect of HP on dopaminergic neurons in an invivo 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced PD mouse model. Animals were assigned to four groups: (1) Group 1(vehicle-treatedgroup), (2) Group 2(MPTPonlytreated group), (3) Group 3(MPTP+ saline-treated/$ST_{36}$ group), and (4) Group 4(MPTP+HP-treated/$ST_{36}$ group). HP at $20{\mu}L$ of 48 mg/kg dose was injected at $ST_{36}$ for 4 weeks at 2-day intervals. MPTP in saline was injected intraperitoneally each day for 5 days from the $8_{th}$ treatment of HP. We performed the pole test and rota-rod test on the first and seventh day after the last MPTP injection. To investigate the effect of HP on dopaminergic neurons, we performed analysis in the striatum and the substantia nigra of mouse brain after treatment with HP and/or MPTP. Results : Treatment with HP had no influence on cell proliferation and caused no cell toxicity in $PC_{12}$ and $HT_{22}$ cells. Our study showed that HP significantly prevented cell loss and protected neurites against MPP+ toxicity. Although the invivo treatment of HP herbal acupuncture at $ST_{36}$ showed a tendency to improve movement ability and protected dopaminergic cells and fibers in the substantia nigra and the striatum, it did not show significant changes compared with the MPTP treated group. Conclusions : These data suggest that HP could be a potential treatment strategy in neurodegenerative diseases such as Parkinson's disease.

• 대한본초학회지
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• 제23권3호
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• pp.53-60
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• 2008

Objectives : Oxidative stress has a critical role in neurodegenerative diseases. In this study, we investigated the antioxidant and neuroprotective effects of the ethanolic extract of Banryong-hwan (BRHE) in SH-SY5Y cells and primary rat mesencephalic dopaminergic neurons. Methods : To assess the antioxidant effects, we carried out 1,1-diphenyl-2-picrylhydrazyl(DPPH) free radical scavenging assay, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)(ABTS) radical cation decolorization assay, and determination of total polyphenolic content. We evaluated the effect of BRHE treatment on neuroprotection against 6-hydroxydopamine(6-OHDA) toxicity using thiazolyl blue tetrazolium bromide(MTT) assay, nitric oxide(NO) assay, reactive oxygen species(ROS) assay in SH-SY5Y cells and tyrosine hydroxylase(TH) immunocytochemistry in primary rat mesencephalic dopaminergic neurons. Results : BRHE showed IC50 values of 328.10 ${\mu}g/mL$ and 43.12 ${\mu}g/mL$ in DPPH assay and in ABTS assay, respectively. Total polyphenolic content was 180.76 ${\mu}g/mL$. In SH-SY5Y cells, BRHE significantly attenuated the toxicity induced by 6-OHDA at the concentrations of 25-100 ${\mu}g/mL$ pre- and post- treatment in MTT assay. While 6-OHDA increased the NO and ROS contents, BRHE decreased them in a dose dependent manner. Moreover, in primary dopaminergic neuron culture, BRHE significantly protect-ed the dopaminergic cell loss against 6-OHDA toxicity up to 136% at the concentration of 75 ${\mu}g/mL$. Conclusions : These results demonstrate that BRHE has neuroprotective effect against 6-OHDA induced neurotoxicity through decreasing NO and ROS generation.

• Biomolecules & Therapeutics
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• 제11권4호
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• pp.214-223
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• 2003

Methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA) have become popular recreational drugs of abuse in many countries. Although the neurotoxic damage caused by METH and MDMA is characterized by degeneration of the dopaminergic and serotonergic systems in brain, the molecular and cellular mechanisms remain to be clarified. Therefore, the purposes of this study were to confirm the capability of METH and MDMA to induce apoptosis and to clarify the action of its molecular mechanism by using serotonergic JAR cells and dopaminergic SK-N-SH cells. METH and MDMA were dose-dependently cytotoxic to human serotonergic JAR cells and dopaminergic SK-N-SH cells. The morphological change of apoptosis was found in Giemsa staining and TUNEL and further verified in DNA fragmentation analysis. Immunoblotting analysis revealed proteolytic cleavage of caspase-3 and -9 and change of bcl-2 and bax proteins. These results suggest that METH and MDMA may induce caspase-dependent apoptosis via the mitochondrial cell death pathway and METH and MDMA-induced neurotoxicity may happen to broadly and independently of both dopaminergic and serotonergic systems.