• 제목/요약/키워드: Dopaminergic

검색결과 346건 처리시간 0.031초

가토신장기능에 미치는 측뇌실내 Haloperidol의 영향 (Influence of Intracerebroventricular Haloperidol on the Renal Function of the Rabbit)

  • 김중기;최봉규;국영종
    • 대한약리학회지
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    • 제18권2호
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    • pp.103-117
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    • 1982
  • 신장기능 조절에 있어서 중추의 dopaminergic system의 역할을 구명하고자 dopamine의 선택적 길항제인 haloperidol을 가토의 측뇌실내로 투여하여 신장기능의 변동을 관찰하였다. Haloperidol 15와 $50{\mu}g/kg$투여시 항이뇨작용을 나타냈으며, $15{\mu}g/kg$의 경우는 주로 세뇨관에서 Na재흡수의 촉진에 의하였으며, $50{\mu}g/kg$의 경우에는 주로 세뇨관에서의 수분재흡수가 뚜렷하였다. 그러나 $150{\mu}g/kg$의 경우에서는 뚜렷한 이뇨작용을 볼 수 있었으며 이때 신혈류 및 사구체 여과율에는 유의한 변동을 볼 수 없었으나 세뇨관에서 Na재흡수가 현저히 억제되어 natriuresis 및 kaliuresis 가 출현되었다. 한편 dopamine은 5, 15, 50, $150{\mu}g/kg$의 양을 측뇌실내로 투여하였을때 투여랑에 대체로 비례하는 항이뇨효과를 관찰할 수 있었다. 여기에서 5, $15{\mu}g/kg$의 소량에 의하여는 그 항이뇨작용이 주로 신세뇨관에 있어서 Na재흡수의 촉진에 기인하였으나 $50{\mu}g/kg$이사의 양에서는 그 외에도 신혈류 및 사구체 여과율의 감소가 더욱 뚜렷하여짐을 볼 수 있었다. Haloperidol $150{\mu}g/kg$ 투여후에 dopamin을 투여하였을 때 $15{\mu}g/kg$ dopamine의 효과는 감퇴되었으나, 50, $150{\mu}g/kg$ dopamin의 항이뇨효과는 차단되지 아니하였으며 dopamine양의 증가에 따라 haloperidol의 이뇨작용이 소실됨을 볼 수 있었다. 이상의 실험결과는 대량의 haolperidol은 중추의 dopamine receptor에 대한 상경적 길항에 의하여 이뇨작용을 나타낸 것으로 해석되며, 소량의 haloperidol은 dopaminergic neurone에 있는 autoreceptor의 차단작용의 결과 항이뇨 작용이 나타난 것으로 추측되었다.

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Nicotine Suppresses TNF-${\alpha}$ Expression in Human Fetal Astrocyte through the Modulation of Nuclear Factor-${\kappa}B$ Activation

  • Son, Il-Hong;Park, Yong-Hoon;Yang, Hyun-Duk;Lee, Sung-Ik;Han, Sun-Jung;Lee, Jai-Kyoo;Ha, Dae-Ho;Kang, Hyung-Won;Park, Joo-Young;Lee, Sung-Soo
    • Molecular & Cellular Toxicology
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    • 제4권2호
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    • pp.106-112
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    • 2008
  • Parkinson's disease (PD) progresses severely by a gradual loss of dopaminergic neurons in the substantia nigra (SN). Epidemiological studies showed that the incidences of PD were reduced by smoking of which the major component, nicotine might be neuroprotective. But the function of nicotine, which might suppress the incidences of PD, is still unknown. Fortunately, recently it was reported that a glial reaction and inflammatory processes might participate in a selective loss of dopaminergic neurons in the SN. The levels of tumour necrosis factor (TNF)-${\alpha}$ synthesised by astrocytes and microglia are elevated in striatum and cerebrospinal fluid (CSF) in PD. TNF-${\alpha}$ kills the cultured dopaminergic neurons through the apoptosis mechanism. TNF-${\alpha}$ release from glial cells may mediate progression of nigral degeneration in PD. Nicotine pretreatment considerably decreases microglial activation with significant reduction of TNF-${\alpha}$ mRNA expression and TNF-${\alpha}$ release induced by lipopholysaccharide (LPS) stimulation. Thus, this study was intended to explore the role of nicotine pretreatment to inhibit the expressions of TNF-${\alpha}$ mRNA in human fetal astrocytes (HFA) stimulated with IL-$1{\beta}$. The results are as follows: HFA were pretreated with 0.1, 1, and $10{\mu}g/mL$ of nicotine and then stimulated with IL-$1{\beta}$ (100 pg/mL) for 2h. The inhibitory effect of nicotine on expressions of TNF-${\alpha}$ mRNA in HFA with pretreated $0.1{\mu}g/mL$ of nicotine was first noted at 8hr, and the inhibitory effect was maximal at 12 h. The inhibitory effect at $1{\mu}g/mL$ of nicotine was inhibited maximal at 24 h. Cytotoxic effects of nicotine were noted above $10{\mu}g/mL$ of nicotine. Moreover, Nicotine at 0.1, 1 and $10{\mu}g/mL$concentrations significantly inhibited IL-$1{\beta}$-induced TF-${\kappa}B$ activation. Collectively, these results indicate that in activated HFA, nicotine may inhibit the expression of TNF-${\alpha}$ mRNA through the pathway which suppresses the NF-${\kappa}B$ activation. This study suggests that nicotine might be neuroprotective to dopaminergic neurons in the SN and reduce the incidences of PD.

The Role of Spinal Dopaminergic Transmission in the Analgesic Effect of Nefopam on Rat Inflammatory Pain

  • Kim, Do Yun;Chae, Joo Wung;Lim, Chang Hun;Heo, Bong Ha;Park, Keun Suk;Lee, Hyung Gon;Choi, Jeong Il;Yoon, Myung Ha;Kim, Woong Mo
    • The Korean Journal of Pain
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    • 제29권3호
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    • pp.164-171
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    • 2016
  • Background: Nefopam has been known as an inhibitor of the reuptake of monoamines, and the noradrenergic and/or serotonergic system has been focused on as a mechanism of its analgesic action. Here we investigated the role of the spinal dopaminergic neurotransmission in the antinociceptive effect of nefopam administered intravenously or intrathecally. Methods: The effects of intravenously and intrathecally administered nefopam were examined using the rat formalin test. Then we performed a microdialysis study to confirm the change of extracellular dopamine concentration in the spinal dorsal horn by nefopam. To determine whether the changes of dopamine level are associated with the nefopam analgesia, its mechanism was investigated pharmacologically via pretreatment with sulpiride, a dopaminergic D2 receptor antagonist. Results: When nefopam was administered intravenously the flinching responses in phase I of the formalin test were decreased, but not those in phase II of the formalin test were decreased. Intrathecally injected nefopam reduced the flinching responses in both phases of the formalin test in a dose dependent manner. Microdialysis study revealed a significant increase of the level of dopamine in the spinal cord by intrathecally administered nefopam (about 3.8 fold the baseline value) but not by that administered intravenously. The analgesic effects of intrathecally injected nefopam were not affected by pretreatment with sulpiride, and neither were those of the intravenous nefopam. Conclusions: Both the intravenously and intrathecally administered nefopam effectively relieved inflammatory pain in rats. Nefopam may act as an inhibitor of dopamine reuptake when delivered into the spinal cord. However, the analgesic mechanism of nefopam may not involve the dopaminergic transmission at the spinal level.

도파민 세포에서 Paraquat에 의한 헴산화효소-1의 유도 (Paraquat Induced Heme Oxygenase-1 in Dopaminergic Cells)

  • 전홍성
    • KSBB Journal
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    • 제20권1호
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    • pp.21-25
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    • 2005
  • 흔하게 사용되어온 제초제인 paraquat는 파킨슨병의 원인이 될 수 있는 유력한 위험 요소이다. 헴산화효소-1(HO-1)은 산화적 스트레스와 소포체 스트레스의 marker인데, 여러 가지 자극에 의해 heme을 분해하여 biliverdin, 일산화탄소, 철 성분으로 전환시킨다 본 연구에서는 뇌의 흑색질 유래의 도파민 세포주 SN4741에서 paraquat가 시간별, 농도별로 HO-1을 활성화시키는 기작을 조사하였다. HO-1이 Paraquat에 의해 활성화되는 것은 주로 유전자 전사 수준에서 조절되었다. HO-1 유전자의 promoter와 5' enhancer인 El, E2를 결실시킨 실험에서, E2 enhancer가 도파민 세포에서 paraquat에 의한 HO-1 유전자 발현을 유도하는 핵심 부위로 판명되었다 E2 enhancer 부위를 돌연변이 시킨 실험 결과는 전사인자 활성 단백질-1 (AP-1) 결합부위를 통해 HO-1 발현이 유도됨을 밝히게 되었다. 또한, 도파민 세포에서 HO-1 유전자 발현의 조절과 신호전달 과정의 관계를 조사하기 위해 MAP kinase들의 특이적 저해제를 처리하고 paraquat로 자극을 준 결과, JNK 저해제인 SP600125가 가장 현저하게 paraquat에 의한 HO-1 발현을 억제하였다. 결론적으로, 도파민 세포에서 paraquat가 HO-1을 유도하는 데는 E2 enhancer가 중요하게 작용하고, AP-1과 JNK 경로를 통해 HO-1 발현이 조절된다는 사실을 처음으로 밝히게 되었다.

인삼양영탕(人蔘養營湯)의 산화적 stress에 대한 뇌세포 보호효과 (Neuroprotective Effect of Insamyangyung-tang)

  • 김승현;이창훈;이진무;조정훈;장준복;이경섭
    • 대한한방부인과학회지
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    • 제22권1호
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    • pp.1-14
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    • 2009
  • Purpose: Oxidative stress was thought to play a critical role in neurodegenerative disease. Many in vivo and in vitro reports explained the possible pathway of human aging. But in therapeutic aspects, there was no clear answers to prevent aging associated with neural diseases. In this study, we investigated the antioxidant and neuroprotective effects of the Insamyangyung-tang (IYT). Methods: To estimate the antioxidant effects, we carried out 1.1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, 2,2'-azinobis-(3- ethylbenzothiazoline-6- sulfonic acid (ABTS) radical cation decolorization assay, and measurement of total polyphenolic content. To evaluate neuroprotective effect of IYT in vitro. We performed thiazolyl blue tetrazolium bromide (MTT) assay, reactive oxygen species (ROS) creation in SH-SY5Y. Tyrosine hydroxylase (TH) immunocytochemistry, nitric oxide (NO) assay, and TNF-${\alpha}$ assay in primary rat mesencephalic dopaminergic neurons. Results: The $IC_{50}$ values were $571.6{\mu}g/m{\ell}$ and $202.3{\mu}g/m{\ell}$ in DPPH and ABTS assay respectively. Total polyphenolic content was 1.05%. In SH-SY5Y culture, IYT significantly increased the decreased cell viability by 6-OHDA at the concentrations of $10{\mu}g/m{\ell}$ in pre-treatment group, $10-100{\mu}g/m{\ell}$ in post-treatment group, and $100{\mu}g/m{\ell}$ in co-treatment group. The production of ROS induced by 6-OHDA was significantly inhibited in IYT treated group. In mesencephalic dopaminergic cell culture, the IYT group reduced the dopaminergic cell loss against 6-OHDA toxicity and the production of No and TNF-${\alpha}$ at the concentration of $0.2{\mu}g/m{\ell}$. Conclusion: These results showed that IYT has antioxidant and neuroprotectctive effects in the dopaminergic cells through decreasing the production of ROS, NO and TNF-${\alpha}$ which can cause many neurodegenerative changes in brain cell.

육울탕(六鬱湯)의 산화적 스트레스에 대한 뇌세포 보호효과 (Neuroprotective Effect of Yukul-tang against the Oxidative Stress)

  • 정선형;이진무;이창훈;조정훈;장준복;이경섭
    • 대한한방부인과학회지
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    • 제22권1호
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    • pp.15-30
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    • 2009
  • Purpose: In this rapidly aging society, the research and development of traditional oriental medicine treatment is one of the critical factors to protect the increasing neuro-degenerative disorders. In this study, we wanted to verify the effect of Yukul-tang (YUT) on neuro-degenerative disease model by assessing the antioxidant and anti-inflammation effects. Methods: To assess the antioxidant effects of YUT, we carried out DPPH radical and ABTS radical scavenging assays and determined the total polyphenolic contents in YUT. To evaluate the neuro-protective effects of YUT, we performed the MTT and ROS assays and TH immunohistochemistry, NO and TNF-${\alpha}$ assays in SH-SY5Y or mesencephalic dopaminergic neurons damaged by 6-OHDA. Results: The treatment of YUT showed eliminating effects on DPPH radical and ABTS radical. it showed deterring effects on ROS, NO and TNF-${\alpha}$ and protecting effects on TH-positive cell in SH-SY5Y cells or mesencephalic dopaminergic neurons. Especially in the case of the treatment of YUT with 0.2ug/mL + 6-OHDA 10uM, the protective effect on dopaminergic neurons was most outstanding. Conclusion: In this study, we have demonstrated that YUT has an antioxidant effect and a neuro-protective effect on neuro-degenerative disease model caused by neurotoxin such as 6-OHDA. The results of our present study suggest that YUT can be useful agent to prevent and to treat neuro-degenerative diseases.