• 제목/요약/키워드: Nitric oxide inhibitor

검색결과 442건 처리시간 0.034초

The Regulatory Mechanism of Cerebral Blood How of Adenosine A2 Receptor Agonist in the Rats

  • Kang, Hyung-Kil;Shin, In-Chul
    • Biomolecules & Therapeutics
    • /
    • 제12권2호
    • /
    • pp.68-73
    • /
    • 2004
  • This study was performed to investigate the regulatory mechanism of cerebral blood How of adenosine $A_2$ receptor agonist in the rats, and to define whether its mechanism is mediated by nitric oxide (NO), adenylate cyclase and guanylate cyclase. In pentobarbital-anesthetized, pancuronium-paralyzed and artificially ventilated male Sprague-Dawley rats, all drugs were applied topically to the cerebral cortex. Blood flow from cerebal cortex was measured using laser-Doppler flowmetry. Topical application of an adenosine $A_2$ receptor agonist [5'-(N-cyclopropyl)-carboxamidoadenosine (CPCA; 4 umol/l)] increased cerebral blood flow. This effect of CPCA (4 umol/l) was blocked by pretreatment with NO synthase inhibitor [$N^G$-nitro-L-argine methylester (L-NAME; 140 umol/l)] and adenylate cyclase inhibitor [MDL-12,330 (20 umol/l)]. But the effect of CPCA (4 umol/l) was not blocked by pretreatment with guanylate cyclase inhibitor [LY-83,583 (10 umol/l)]. These results suggest that adenosine $A_2$ receptor increases cerebral blood How. It seems that this action of adenosine $A_2$ receptor is mediated via the NO and the activation of adenylate cyclase in the cerebral cortex of the rats.

토끼 적출 신동맥에 있어서 acetylcholine에 의한 내피세포 의존성 이완작용에 대한 nitric oxide와 prostanoid의 연관성 (Involvement of nitric oxide and prostanoid on the endothelium -dependent vasodilatation by acetylcholine in the isolated rabbit renal artery)

  • 김주헌;심철수;전석철
    • 대한수의학회지
    • /
    • 제41권3호
    • /
    • pp.299-304
    • /
    • 2001
  • 토끼 적출 신동맥에 있어서 acetylcholin(Ach)에 의한 이완작용에 대한 nitric oxide(NO) 합성 억제제인 $N^{G}$-nitro-L-arginine methyl ester(L-NAME)과 prostanoid 합성 억제제인 indomethacin의 영향을 관찰하였다. Ach($10^{-8}-3{\times}10^{-5}M$)에 대한 이완작용은 내피세포를 제거시킴으로서 완전히 사라졌다. L-NAME ($10^{-4}M$)은 Ach ($10^{-8}-3{\times}10^{-5}M$)의 이완작용을 현저히 감소시켰으며 L-arginine ($10^{-3}M$)에 의해 Ach의 이완작용에 대한 L-NAME ($10^{-4}M$)의 억제효과가 현저히 약하게 나타났다. Indomethacin ($10^{-6}M$)은 Ach ($10^{-8}-3{\times}10^{-5}M$)의 이완작용에 영향을 미치지 못하였다. L-NAME ($10^{-4}M$)에 indomethacin ($10^{-6}M$)의 첨가는 Ach ($10^{-8}-3{\times}10^{-5}M$)의 이완작용이 L-NAME ($10^{-4}M$) 단독의 경우보다 더 큰 억제효과를 나타내었다. 이와 같은 결과로 토끼적출 신동맥에서 Ach은 내피세포 의존성 이완작용을 나타내며, NO와 prostanoid가 수반되어 나타나는 것으로 사료되어진다.

  • PDF

Inhibitory Effect of Chan-Su on the Secretion of PGE2 and NO in LPS-stimulated BV2 Microglial Cells

  • Kim, Min-Hee;Lyu, Ji-Hyo;Lyu, Sun-Ae;Hong, Sang-Hoon;Kim, Won-Il;Yoon, Hwa-Jung;Ko, Woo-Shin
    • 동의생리병리학회지
    • /
    • 제22권5호
    • /
    • pp.1315-1321
    • /
    • 2008
  • 본 논문은 오랫동안 민간요법으로 염증치료에 사용되어오던 섬수가 lipopolysaccharide(LPS)-자극된 BV2 소교 세포의 nitric oxide(NO) 분비에 미치는 효과에 대해 연구한 내용이다. 실험 결과 섬수는 세포 생존력에 대한 영향 없이 BV2 소교 세포에서 NO 분비를 억제시켰고, nitric oxide synthase (iNOS) 단백질도 감소시켰다. 또한 섬수는 prostaglandin E2 (PGE2) 생산 및 cyclooxygenase (COX)-2 발현을 저지하였고, proinflammatory cytokines과 ${IkB-\alpha}$감소를 억제시켰다. 따라서 섬수가 $I{\kappa}B-{\alpha}$감소를 억제함으로써 NO 합성을 저해하여 항염증작용을 할 수 있다는 내용이다.

갈퀴나물 에탄올 추출물의 RAW264.7 대식세포에서 LPS(Lipopolysaccharide)로 유도된 nitric oxide 및 prostaglandin E2 생성 저해효과 (Inhibitory effects of ethanol extract from Vicia amoena on LPS(Lipopolysaccharide) induced nitric oxide and prostaglandin E2 production in RAW264.7 macrophage cell)

  • 남정환;박수진
    • 예술인문사회 융합 멀티미디어 논문지
    • /
    • 제9권6호
    • /
    • pp.443-450
    • /
    • 2019
  • 본 연구에서는 갈퀴나물(Vicia amoena) 전초를 이용한 에탄올 추출물의 세포독성과 항염증 활성 효과를 평가하였다. RAW264.7 cell(대식세포)에서 염증 매개 물질인 lipopolysaccharide(LPS)로 염증을 유발시켜 nitric oxide (NO) 및 prostaglandin E2 (PGE2)같은 염증 유발 인자들의 생성 저해효과를 확인하였다. 갈퀴나물 에탄올 추출물의 염증 유발 인자 억제 시 저해효과를 측정하였을 때 nitric oxide 및 prostaglandin E2 생성을 농도 의존적으로 현저하게 저해하는 농도인 40 ㎍/㎖의 농도에서 LPS에 의해 유도된 NO를 36.0 ± 0.5 % 저해하였으며, 특히 PGE2에서는 88.0 ± 0.8 % 만큼 유의성 있는 저해효과를 나타내었다. 따라서 본 연구결과는 갈퀴나물의 에탄올 추출물이 유의성 있는 항염증 효과를 나타내며, 이러한 효능은 예방의학적 가능성을 충분히 가지고 있기에 염증성 질환의 예방을 위한 항염증 소재로의 개발 가능성을 제시할 수 있을 것으로 기대된다. 차후 에탄올 추출물의 보다 다양한 농도 및 유기용매 분획물에서 염증반응을 매개하는 iNOS·COX-2 등 의 다양한 효소의 발현과 Iκ-Bα의 분해 등 염증반응의 신호전달물질의 변화에 대한 추가적인 연구가 필요할 것으로 판단된다.

Molecular Mechanism of NO-induced Cell Death of PC12 Cells by $IFN{\gamma}\;and\;TNF{\alpha}$

  • Yi, Seh-Yoon;Han, Seon-Kyu;Lee, Jee-Yeon;Yoo, Young-Sook
    • Molecular & Cellular Toxicology
    • /
    • 제1권3호
    • /
    • pp.196-202
    • /
    • 2005
  • Nitric oxide (NO) is a small, diffusible, and highly reactive molecule, which plays dichotomous regulatory roles under physiological and pathological conditions. NO promotes apoptosis in some cells, and inhibits apoptosis in other cells. In the present study, we attempted to characterize the NO signaling pathway and cellular response in PC12 cells treated with cytokines. $IFN{\gamma}\;and\;TNF{\alpha}$ treatment resulted in a synergistic increase of nitrite accumulation, with the induction of inducible nitric oxide synthase (iNOS) in the PC12 cells. Moreover, as nitrite concentration increased, cell viability decreased. In order to explore MAP kinase involvement in nitric oxide production resultant from $IFN{\gamma}\;and\;TNF{\alpha}$ stimulation, we measured the activation of MAP kinase using specific MAP kinase inhibitors. PC12 cells pretreated with SB203580, a p38 MAP kinase-specific inhibitor, resulted in the inhibition of iNOS expression and NO production. However, PD98059, an ERK/MAP kinase-specific inhibitor, was not observed to exert such an effect. In addition, Stat1 activated by $IFN{\gamma}\;and\;TNF{\alpha}$ was interacted with p38 MAPK. These data suggest that p38 MAP kinase mediates cytokine-mediated iNOS expression in the PC12 cells, and Jak/Stat pathway interferes with p38 MAPK signaling pathway.

The Effect of Carbon Monoxide on L-type Calcium Channel Currents in Human Intestinal Smooth Muscle Cells

  • Lim, In-Ja
    • The Korean Journal of Physiology and Pharmacology
    • /
    • 제7권6호
    • /
    • pp.357-362
    • /
    • 2003
  • Carbon monoxide (CO) is low molecular weight oxide gas that is endogenously produced under physiological conditions and interacts with another gas, nitric oxide (NO), to act as a gastrointestinal messenger. The aim of this study was to determine the effects of exogenous CO on L-type calcium channel currents of human jejunal circular smooth muscle cells. Cells were voltage clamped with 10 mM barium ($Ba^{2+}$) as the charge carrier, and CO was directly applied into the bath to avoid perfusion induced effects on the recorded currents. 0.2% CO was increased barium current ($I_{Ba}$) by $15{\pm}2$% ($mean{\pm}S.E.$, p<0.01, n=11) in the cells. To determine if the effects of CO on barium current were mediated through the cGMP pathway, cells were pretreated with 1-H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ, $10{mu}M$), a soluble guanylyl cyclase inhibitor, and exogenous CO (0.2%) had no effect on barium currents in the presence of ODQ ($2{\pm}1$% increase, n=6, p>0.05). CO mediates inhibitory neurotransmission through the nitric oxide pathway. Therefore, to determine if the effects of CO on L-calcium channels were also mediated through NO, cells were incubated with $N^G-nitro-L-arginine$ (L-NNA, 1 mM), a nitric oxide synthase inhibitor. After L-NNA pretreatment, 0.2 % CO did not increase barium current ($4{\pm}2$% increase, n=6, p>0.05). NO donor, SNAP ($20{\mu}M$) increased barium current by $13{\pm}2$% (n=6, p<0.05) in human jejunal smooth muscle cells. These data suggest that CO activates L-type calcium channels through NO/cGMP dependant mechanism.

Involvement of nitric oxide-induced NADPH oxidase in adventitious root growth and antioxidant defense in Panax ginseng

  • Tewari, Rajesh Kumar;Kim, Soohyun;Hahn, Eun-Joo;Paek, Kee-Yoeup
    • Plant Biotechnology Reports
    • /
    • 제2권2호
    • /
    • pp.113-122
    • /
    • 2008
  • Nitric oxide (NO) affects the growth and development of plants and also affects plant responses to various stresses. Because NO induces root differentiation, we examined whether or not it is involved in increased ROS generation. Treatments with sodium nitroprusside (SNP), an NO donor, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a specific NO scavenger, and $N{\omega}-nitro-{\text\tiny{L}}-arginine$ methyl ester hydrochloride (${\text\tiny{L}}-NAME$), an NO synthase (NOS) inhibitor, revealed that NO is involved in the adventitious root growth of mountain ginseng. Supply of an NO donor, SNP, activates NADPH oxidase activity, resulting in increased generation of $O_2{^{{\cdot}-}}$, which subsequently induces growth of adventitious roots. Moreover, treatment with diphenyliodonium chloride (DPI), an NADPH oxidase inhibitor, individually or with SNP, inhibited root growth, NADPH oxidase activity, and $O_2{^{{\cdot}-}}$ anion generation. Supply of the NO donor, SNP, did not induce any notable isoforms of enzymes; it did, however, increase the activity of pre-existing bands of NADPH oxidase, superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase. Enhanced activity of antioxidant enzymes induced by SNP supply seems to be responsible for a low level of $H_2O_2$ in the adventitious roots of mountain ginseng. It was therefore concluded that NO-induced generation of $O_2{^{{\cdot}-}}$ by NADPH oxidase seems to have a role in adventitious root growth of mountain ginseng. The possible mechanism of NO involvement in $O_2{^{{\cdot}-}}$ generation through NADPH oxidase and subsequent root growth is discussed.

Activation of the cGMP/Protein Kinase G Pathway by Nitric Oxide Can Decrease TRPV1 Activity in Cultured Rat Dorsal Root Ganglion Neurons

  • Jin, Yun-Ju;Kim, Jun;Kwak, Ji-Yeon
    • The Korean Journal of Physiology and Pharmacology
    • /
    • 제16권3호
    • /
    • pp.211-217
    • /
    • 2012
  • Recent studies have demonstrated that nitric oxide (NO) activates transient receptor potential vanilloid subtype 1 (TRPV1) via S-nitrosylation of the channel protein. NO also modulates various cellular functions via activation of the soluble guanylyl cyclase (sGC)/protein kinase G (PKG) pathway and the direct modification of proteins. Thus, in the present study, we investigated whether NO could indirectly modulate the activity of TRPV1 via a cGMP/PKG-dependent pathway in cultured rat dorsal root ganglion (DRG) neurons. NO donors, sodium nitroprusside (SNP) and S-nitro-N-acetylpenicillamine (SNAP), decreased capsaicin-evoked currents ($I_{cap}$). NO scavengers, hemoglobin and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO), prevented the inhibitory effect of SNP on $I_{cap}$. Membrane-permeable cGMP analogs, 8-bromoguanosine 3', 5'-cyclic monophosphate (8bromo-cGMP) and 8-(4chlorophenylthio)-guanosine 3',5'-cyclic monophosphate (8-pCPT-cGMP), and the guanylyl cyclase stimulator YC-1 mimicked the effect of SNP on $I_{cap}$. The PKG inhibitor KT5823 prevented the inhibition of $I_{cap}$ by SNP. These results suggest that NO can downregulate the function of TRPV1 through activation of the cGMP/PKG pathway in peripheral sensory neurons.

UV-B 조사시 옥수수 잎의 산화적 스트레스에 대한 Nitric Oxide의 보호효과 (Protective Effect of Nitric Oxide against Oxidative Stress under UV-B Radiation in Maize Leaves)

  • 김태윤;조명환;홍정희
    • 한국환경과학회지
    • /
    • 제19권12호
    • /
    • pp.1323-1334
    • /
    • 2010
  • The effect of nitric oxide (NO) on antioxidant system and protective mechanism against oxidative stress under UV-B radiation was investigated in leaves of maize (Zea mays L.) seedlings during 3 days growth period. UV-B irradiation caused a decrease of leaf biomass including leaf length, width and weight during growth. Application of NO donor, sodium nitroprusside (SNP), significantly alleviated UV-B stress induced growth suppression. NO donor permitted the survival of more green leaf tissue preventing chlorophyll content reduction and of higher quantum yield for photosystem II than in non-treated controls under UV-B stress, suggesting that NO has protective effect on chloroplast membrane in maize leaves. Flavonoids and anthocyanin, UV-B absorbing compounds, were significantly accumulated in the maize leaves upon UV-B exposure. Moreover, the increase of these compounds was intensified in the NO treated seedlings. UV-B treatment resulted in lipid peroxidation and induced accumulation of hydrogen peroxide ($H_2O_2$) in maize leaves, while NO donor prevented UV-B induced increase in the contents of malondialdehyde (MDA) and $H_2O_2$. These results demonstrate that NO serves as antioxidant agent able to scavenge $H_2O_2$ to protect plant cells from oxidative damage. The activities of two antioxidant enzymes that scavenge reactive oxygen species, catalase (CAT) and ascorbate peroxidase (APX) in maize leaves in the presence of NO donor under UV-B stress were higher than those under UV-B stress alone. Application of 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3- oxide (PTIO), a specific NO scavenger, to the maize leaves arrested NO donor mediated protective effect on leaf growth, photosynthetic pigment and free radical scavenging activity. However, PTIO had little effect on maize leaves under UV-B stress compared with that of UV-B stress alone. $N^{\omega}$-nitro-L-arginine (LNNA), an inhibitor of nitric oxide synthase (NOS), significantly increased $H_2O_2$ and MDA accumulation and decreased antioxidant enzyme activities in maize leaves under UV-B stress. This demonstrates that NOS inhibitor LNNA has opposite effects on oxidative resistance. From these results it is suggested that NO might act as a signal in activating active oxygen scavenging system that protects plants from oxidative stress induced by UV-B radiation and thus confer UV-B tolerance.

Inhibitory Activity of Medicinal Herbs on Nitric Oxide Synthesis in Activated Macrophages

  • Lee, Hwa-Jin;Kim, Ji-Sun;Jin, Chang-Bae;Ryu, Jae-Ha
    • Natural Product Sciences
    • /
    • 제11권1호
    • /
    • pp.16-21
    • /
    • 2005
  • Nitric Oxide (NO), derived from L-arginine, is produced by two types (constitutive and inducible) of nitric oxide synthase (NOS: cNOS and iNOS). The NO produced in large amounts by the iNOS is known to be responsible for the vasodilation and hypotension observed in septic shock, cancer metastasis and inflammation. The inhibitors of iNOS, thus, may be useful candidates for the treatment of inflammatory diseases accompanied by the overproduction of NO. We prepared alcoholic extracts of herbal drugs which have been used for the treatment of inflammation in oriental medicine. We have screened the inhibitory activity of NO production in lipopolysaccharide (LPS)-activated macrophages after the treatment of these extracts. Among 82 kinds of extracts of herbal drugs, 35 extracts showed the potent inhibitory activity of NO production above 50% at the concentration of $50\;{\mu}g/mL$. The inhibitory activities of NO production were also evaluated for several solvent fractions at two different concentrations. Especially, hexane and EtOAc fractions of Alpinia officinarum, Angelica gigas, Ostericum koreanum, Saussurea lappa, Torilis japonica, and hexane fractions of Agrimonia pilosa, Machilus thunbergii, Hydrangea serrata, Magnolia obovata, Prunella vulgaris, Tussilago farfara, and EtOAC fractions of Perilla frutescence showed a significant activity at 10 and/or $25\;{\mu}g/mL$. In Western blot analysis, the hexane fractions ($5\;{\mu}g/mL$) of Magnolia obovata and Saussurea lappa, and EtOAc fractions ($20\;{\mu}g/mL$) of Hydrangea Serrata, Perilla frutescence and Torilis japonica inhibited the expression of iNOS protein in LPS-activated macrophages. These plants may be promising candidates for the study of the activity-guided purification of active compounds and might be useful for the treatment of inflammatory diseases and endotoxemia accompanying overproduction of NO.