• 제목/요약/키워드: Nitric oxide synthase

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Ovalbumin에 의해서 유도된 inducible nitric oxide synthase 발현에 대한 phenethyl isothiocyanate의 억제효과 (Phenethyl Isothiocyanate Inhibits Ovalbumin-induced Inducible Nitric Oxide Synthase Expression)

  • 신화정;윤형선
    • 한국식품과학회지
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    • 제44권6호
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    • pp.759-762
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    • 2012
  • 이번 실험을 통하여 PEIC가 OVA에 의해 유도된 NF-${\kappa}B$ 활성과 iNOS, COX-2 발현에 어떠한 영향을 미치는지 알아 보았다. PEIC는 OVA에 의해 유도된 NF-${\kappa}B$ 활성을 억제시켰다. 또한 PEIC는 OVA에 의해 유도된 iNOS의 발현도 억제시켰다. 하지만 PEIC는 OVA에 의해 유도된 COX-2 발현은 억제시키지 못하였다. 이러한 결과는 iNOS와 COX-2가 서로 다른 메커니즘에 의해 조절된다는 것을 암시한다. 또한 PEIC는 알러지와 같은 만성적인 질병들을 조절할 수 있는 치료제 개발 및 백신 제조에 중요한 역할을 할 것으로 기대한다.

면역억제제가 Lipopolysaccharide에 의한 생쥐의 간 및 뇌조직의 Nitric Oxide Synthase 활성도의 변화에 미치는 영향 (Effect of Immunosuppressants on Lipopolysaccharide-Induced Changes of Nitric Oxide Synthase Activity in Liver and Brain of Mice)

  • 민병우;한형수;박정숙;김중영
    • 대한약리학회지
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    • 제31권2호
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    • pp.233-239
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    • 1995
  • To verify the effect of immunosuppressants on the endotoxin-induced increase in iNOS activity, the action of immunosuppressants, dexamethasone (1.5 mg/kg), azathioprine (5 mg/kg/day) and cyclosporine (10 mg/kg), were evaluated in mice pretreated with LPS. The intraperitoneal injection of lipopolysaccharide (10 mg/kg) increased the nitric oxide synthase (NOS) activity in the brain and liver to maximum at 1 and 3 hours, respectively. The increase in NOS activity was blocked by the treatment with NOS inhibitor, LNAME(300 mg/kg) and aminoguanidine(100 mg/kg); a protein inhibitor, cycloheximide (10 mg/kg); and a transcription inhibitor of inducible NOS(iNOS), dexamethasone(1.5 mg/kg). Immunosuppressants, azathioprine (5 mg/kg) and cyclosporine (10 mg/kg), effectively blocked the increase in NOS activity. These results suggest that iNOS expression plays an important role in LPS-induced the increase in NOS activity and that immunosuppressants can be used as candidate for therapeutic agents in endotoxemia.

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혈관평활근세포에서 Cyclosporin A에 의한 Nitric Oxide 생성억제를 길항하는 실험적 중재법 (Experimental Intervention to Reverse Inhibition of Nitric Oxide Production by Cyclosporin A in Rat Aortic Smooth Muscle Cells)

  • 김인겸
    • 대한약리학회지
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    • 제32권2호
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    • pp.211-219
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    • 1996
  • The inhibitory effect of cyclosporin A (CsA) on nitric oxide production is not related to the immunosuppressive action of the drug, but to the renal toxicity and arterial hyper-tension. In this study the experimental interventions to reverse the inhibition of nitric oxide production by cyclosporin A in rat aortic smooth muscle cells were examined. CsA inhibited the accumulation of nitrite, the stable end product of nitric oxide, in culture media in a concentration $(0.1{\sim}100{\mu}g/ml)-dependent$ manner. The inhibitory effect of CsA on nitrite accumulation were not antagonized by arginine (10 mM), a substrate of nitric oxide synthase, nor by calcium ionophore A23187 $(7{\mu}M)$. Forskolin, an activator of adenylate cyclase, which enhanced iNOS induction at transcriptional level, completely reversed the inhibitory action of CsA on nitrite accumulation. However, PMA (2 nM) and PDB (50 nM), PKC activators, increased the inhibitory action of CsA on nitrite accumulalion. From these results, it is suggested that cyclic AMP-elevating agents may be candidates of therapeutic agents in prevention and treatment of renal toxicity and arterial hypertension induced by CsA. Among conventional antihypertensive drugs, calcium channel blockers and ${\alpha}-blockers$ are preferred to ${\beta}-blockers$.

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Dexmedetomidine inhibits vasoconstriction via activation of endothelial nitric oxide synthase

  • Nong, Lidan;Ma, Jue;Zhang, Guangyan;Deng, Chunyu;Mao, Songsong;Li, Haifeng;Cui, Jianxiu
    • The Korean Journal of Physiology and Pharmacology
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    • 제20권5호
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    • pp.441-447
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    • 2016
  • Despite the complex vascular effects of dexmedetomidine (DEX), its actions on human pulmonary resistance arteries remain unknown. The present study tested the hypothesis that DEX inhibits vascular tension in human pulmonary arteries through the endothelial nitric oxide synthase (eNOS) mediated production of nitric oxide (NO). Pulmonary artery segments were obtained from 62 patients who underwent lung resection. The direct effects of DEX on human pulmonary artery tension and changes in vascular tension were determined by isometric force measurements recorded on a myograph. Arterial contractions caused by increasing concentrations of serotonin with DEX in the presence or absence of L-NAME (endothelial nitric oxide synthase inhibitor), yohimbine (${\alpha}_2$-adrenoceptor antagonist) and indomethacin (cyclooxygenase inhibitor) as antagonists were also measured. DEX had no effect on endothelium-intact pulmonary arteries, whereas at concentrations of $10^{-8}{\sim}10^{-6}mol/L$, it elicited contractions in endothelium-denuded pulmonary arteries. DEX (0.3, 1, or $3{\times}10^{-9}mmol/L$) inhibited serotonin-induced contraction in arteries with intact endothelium in a dose-dependent manner. L-NAME and yohimbine abolished DEX-induced inhibition, whereas indomethacin had no effect. No inhibitory effect was observed in endothelium-denuded pulmonary arteries. DEX-induced inhibition of vasoconstriction in human pulmonary arteries is mediated by NO production induced by the activation of endothelial ${\alpha}_2$-adrenoceptor and nitric oxide synthase.

Tat-Mediated p66shc Transduction Decreased Phosphorylation of Endothelial Nitric Oxide Synthase in Endothelial Cells

  • Lee, Sang-Ki;Lee, Ji-Young;Joo, Hee-Kyoung;Cho, Eun-Jung;Kim, Cuk-Seong;Lee, Sang-Do;Park, Jin-Bong;Jeon, Byeong-Hwa
    • The Korean Journal of Physiology and Pharmacology
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    • 제16권3호
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    • pp.199-204
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    • 2012
  • We evaluated the role of Tat-mediated p66shc transduction on the activation of endothelial nitric oxide synthase in cultured mouse endothelial cells. To construct the Tat-p66shc fusion protein, human full length p66shc cDNA was fused with the Tat-protein transduction domain. Transduction of TAT-p66shc showed a concentration- and time-dependent manner in endothelial cells. Tat-mediated p66shc transduction showed increased hydrogen peroxide and superoxide production, compared with Tat-p66shc (S/A), serine 36 residue mutant of p66shc. Tat-mediated p66shc transduction decreased endothelial nitric oxide synthase phosphorylation in endothelial cells. Furthermore, Tat-mediated p66shc transduction augmented TNF-${\alpha}$-induced p38 MAPK phosphorylation in endothelial cells. These results suggest that Tat-mediated p66shc transduction efficiently inhibited endothelial nitric oxide synthase phosphorylation in endothelial cells.

고량강으로부터 분리된 galangin의 RAW 264.7 세포주에서 LPS로 유도된 nitric oxide 생성 저해활성 (Inhibitory Effect of Galangin from Alpinia officinarum on Lipopolysaccharide-induced Nitric Oxide Synthesis in RAW 264.7 macrophages)

  • 이화진
    • 한국식품과학회지
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    • 제46권4호
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    • pp.511-515
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    • 2014
  • 각종 염증성 질환 및 패혈증으로 인한 치명적인 저혈압을 예방치료하는 약물 개발을 위한 기초 연구로서 유도성 NOS (inducible nitric oxide synthase, iNOS) 에 의한 NO의 과다 생성을 저해하는 성분을 천연물로부터 찾아내고자 본 연구를 수행하였다. NO 생성 저해활성의 검정은 대식세포주인 RAW 264.7 세포를 LPS로 활성화한 후, 유도되는 iNOS에 의해 생성되는 NO를 Griess 시약을 이용해 $NO_2{^-}$의 형태로 정량하였다. 또한 Western blot 실험 및 RT-PCR 실험을 시행하여 iNOS의 mRNA의 발현 및 단백 합성에 대한 영향을 조사하였다. 고량강(Alpinia officinarum Hance, Zingiberaceae)의 메탄올 추출물로부터 극성에 따른 용매 분획을 시행하여 활성성분을 분리하고 분광학적 분석법을 이용하여 분리한 단일성분이 flavonol 구조인 3,5,7-trihydroxy-2-phenylchromen-4-one (galangin, GLG)임을 확인하였다. 작용기전을 알아보기 위해, Western blot 및 RT-PCR 실험결과, 분리한 flavonol 성분(GLG)의 NO 생성저해 활성은 iNOS mRNA발현을 저해하여 iNOS 효소 단백질의 생성이 억제됨에 기인하는 것으로 확인하였다. 따라서, 고량강 추출물로부터 분리한 flavonol 화합물(GLG)이 iNOS 발현의 억제를 통해 다량의 NO 생산을 저해함으로써, 고량강(Alpinia officinarum)의 NO 과량생성과 관련된 염증성 질환에 대한 응용 가능성이 클 것으로 기대된다.

Purification of Nitric Oxide Synthase from Bovine Pancreas

  • Nam, Suk-Woo;Seo, Dong-Wan;Lee, Young-Jin;Sung, Dae-Seok;Han, Jung-Whan;Lee, Hyang-Woo
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1996년도 춘계학술대회
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    • pp.184-184
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    • 1996
  • Nitric Oxide Synthase(NO synthase: EC.1.14.13.39)는 생체내에서 L-arginine을 기질로 하여 nitric oxide(NO)와 L-citrulline의 생성을 매개하는 효소로서 뇌, 간장, 신장, 체장등 대부분의 주요장기와 근육세포, 신경세포 등 거의 모든 조직에 분포하고 있다. NO synthase에 의해 생성되는 NO는 혈관이완작용, 신경전달 물질로서의 작용, 면역 담당세포에서의 세포 독작용 등 많은 생리현상에 중요한 역할을 하는 것으로 알려져 있다. 특히 체장에서는 췌외분비 기능의 항진에 있어 세포내 cGMP level의 변동이 NO와 연관된다는 사실에 주목하고 있으며 본연구실에서도 이에 관한 연구가 진행중이다. 따라서 본 연구에서는 소 췌조직의 100,000$\times$g cytosol을 효소원으로 하여 다음과 같이 NO synthase의 분리, 정제를 시행하였다. Ammonium sulfate로 30%(176g solid ammonium sulfate/$\ell$) 포화, 침전 후 2',5'-ADP agarose 및 calmodulin-agarose affinity chromatography를 연속적으로 시행하여 NO synthase를 분리하였으며 electrophoresis상에서 약 160kd의 분자량을 나타내었다.

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Porphyromonas gingivalis의 세균내독소가 RAW264.7세포에서의 nitric oxide의 생성과 inducible nitric oxide synthase의 발현에 미치는 영향 및 기전 (Nitric oxide production and inducible nitric oxide synthase expression induced by Porphyromonas gingivalis lipopolysaccharide)

  • 백은영;최은영;최점일;이주연;김성조
    • Journal of Periodontal and Implant Science
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    • 제35권4호
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    • pp.1081-1095
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    • 2005
  • 본 연구는 치주질환 주요 병인균주 중의 하나인 Porphyromonas gingivalis의 세균내독소가 마우스 대식 세포주인 RAW264.7 세포에서의 nitric oxide의 생성과 iNOS의 발현에 미치는 영향을 분석하고 그 기전을 규명하기 위해 수행되었다. Butanol추출법과 phenol-water법에 의해 P. gingivalis 381로부터 세균내독소를 추출하였으며, NO의 생성은 배양 상층액 내의 nitrite 농도를 측정하여 결정하였다. 또한, iNOS의 western blot 분석과 reverse transcription (RT)-PCR 산물의 분석을 수행하였다. P. gingivalis의 세균내독소는 부가적인 자극이 없는 상태에서도 iNOS의 발현과 NO 생성을 유발하였으며, NF- ${\kappa}B$, microtubule polymerization, protein tyrosine kinase, 그리고 protein kinase C 등이 P. gingivalis 세균내독소에 의한 NO 생성에 간여하는 것으로 여겨진다. 또한, P. gingivalis 세균내독소에 의한 NO 생성에는 L-arginine이 요구되었다. P. gingivalis 세균내독소에 의한 NO 생성은 염증성 치주질환의 발병과 진행에 있어 중요한 역할을 하는 것으로 여겨진다.

Parthenolide Inhibits Ovalbumin-Induced cyclooxygenase-2 and Inducible Nitric Oxide Synthase Expression

  • Youn, Hyung-Sun
    • 대한의생명과학회지
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    • 제18권3호
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    • pp.319-323
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    • 2012
  • In recent years, egg allergy has been raised as the most prevalent food hypersensitivity in the pediatric population. One of the major egg allergens is ovalbumin (OVA) which is the major protein in egg white, comprising 54% of its total protein content. Parthenolide isolated from Tanacetum partheniumb has been used to treat many chronic diseases for many years. In the present report, we present biochemical evidence that parthenolide inhibits the nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activation induced by OVA. Parthenolide also inhibits OVA-induced cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression. These data suggest new approaches for the efficient alleviation of the allergic symptoms.