• Journal of Chest Surgery
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• 제32권2호
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• pp.138-143
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• 1999

배경: 혈관 내피층에서 분비되어 평활근층 이완을 일으키는 물질의 본체는 산화질소(nitric oxide, NO)이며 NO synthase(NOS)에는 뇌형(brain NOS, bNOS), 내피세포형(endothelial constitutive NOS, ecNOS) 및 유도형 (inducible NOS, iNOS) 등 세 가지 동위효소가 있음이 알려져 있다. 고혈압은 혈관 내피층 기능 이상을 보임이 알려져 있으나 NOS 동위 효소의 변화를 포함한 세포내 기전은 아직 확실치 않다. 저자들은 고혈압 기전을 구명하기 위한 일환으로 고혈압 혈관에서 NOS 동위효소가 어떻게 변화되는가 조사하고자 하였다. 대상 및 방법: 흰쥐에서 two-kidney, one clip (2K1C) 고혈압과 deoxycorticosterone acetate(DOCA)-salt 고혈압을 일으켰다. 4주 뒤 고혈압이 일어난 것을 확인하고 적출 흉부 대동맥 표본에서 Western blot 분석에 의한 NOS 동위효소 발현 조사 및 비색법에 의한 조직내 산화질소 정량을 하였다. 결과: 2K1C 및 DOCA-salt 흰쥐에서 실험군은 각각의 대조군에 비해 유의하게 높은 혈압을 보였다. 두 고혈압군에서 모두 적출 대동맥 표본의 bNOS 및 ecNOS 단백 발현이 감소되었다. iNOS 단백은 DOCA-salt 고혈압에서 변화를 보이지 않으나 2K1C 고혈압에서는 역시 감소를 보였다. 혈관조직내 산화질소 함량은 두 고혈압에서 모두 유의하게 감소되었다. 결론: 2K1C 및 DOCA-salt 고혈압에서 혈관의 NOS 발현과 산화질소 함량이 감소되어 있으며 이는 고혈압의 유지 기전에 공헌하리라 추측되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제2권4호
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• pp.455-460
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• 1998

The present study was aimed at investigating whether the development of hypertension is related with an altered expression of nitric oxide synthases (NOS) in the kidney. By Western blot analysis, the expression of bNOS and ecNOS isoforms was determined in the kidney of deoxycorticosterone acetate (DOCA)-salt and two-kidney, one clip (2K1C) rats. In DOCA-salt hypertension, the expression of both bNOS and ecNOS was decreased, along with tissue contents of nitrites. In 2K1C hypertension, the nitrite content of the clipped kidney was decreased along with ecNOS levels, whereas neither the nitrite content nor the expression of NOS isoforms was significantly altered in the contralateral non-clipped kidney. These results suggest that the development of hypertension is associated with an altered renal expression of NOS and nitric oxide generation in DOCA-salt and 2K1C rats.

• The Korean Journal of Physiology and Pharmacology
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• 제10권6호
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• pp.337-341
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• 2006

The present study was designed to investigate the protein expression of nitric oxide synthase (NOS) and guanylyl cyclase (GC) activity in ischemia/perfusion (I/R) renal injury in rats. Renal I/R injury was experimentally induced by clamping the both renal pedicle for 40 min in Sprague-Dawley male rats. The renal expression of NOS isoforms was determined by Western blot analysis, and the activity of guanylyl cyclase was determined by the amount of guanosine 3', 5'-cyclic monophosphate (cGMP) formed in response to sodium nitroprusside (SNP), NO donor. I/R injury resulted in renal failure associated with decreased urine osmolality. The expression of inducible NOS (iNOS) was increased in I/R injury rats compared with controls, while endothelial NOS (eNOS) and neuronal NOS (nNOS) expression was decreased. The urinary excretion of NO metabolites was decreased in I/R injury rats. The cGMP production provoked by SNP was decreased in the papilla, but not in glomerulus. These results indicate an altered regulation of NOS expression and guanylyl cyclase activity in I/R-induced nephropathy.

• Journal of Korean Society for Atmospheric Environment
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• 제18권E2호
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• pp.121-128
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• 2002

This study was carried out to investigate if nitric oxide synthase (NOS) inhibitors modulate airway inflammation induced by diesel exhaust particles (DEP). N$\^$G/-nitro-L-arginine methyl ester (L-NAME), a potent constitutive NOS (cNOS) inhibitor, and aminoguanidine (AG), a selective inducible NOS (iNOS) inhibitor, were administered to mice in their drinking water for 7 weeks. Airway inflammation was elicited by the repeated intratracheal administration of DEP. The results showed that macrophages, inflammatory eosinophils and neutrophils in bronchoalveolar lavage (BAL) fluids by intratracheal DEP instillation were significantly suppressed in the mice treated with two NOS inhibitors toghther with DEP. The suppression of these cells was more effective in AG treated groups than in L -NAME treated groups. NOS inhibitor treatment also reduced interleukin -5 (IL-5 in the BAL fluids and lung homogenates. Additionally, it was found that eosinophil peroxidase (EPO) activity in the BAL fluids was also decreased by NOS inhibitor treatment. These results suggest that nitric oxide (NO) is produced in airway inflammation by repeated DEP instillation, and that iNOS inhibition as well as cNOS inhibition can play a modulating role in this airway inflammation by DEP.

• The Korean Journal of Physiology and Pharmacology
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• 제16권5호
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• pp.333-337
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• 2012

Gene expression of neuronal nitric oxide synthase (nNOS) changes in the hypothalamic paraventricular nucleus (PVN) depending on feeding conditions, which is decreased during food deprivation and restored by refeeding, and phosphorylated cAMP response element binding protein (pCREB) was suggested to play a role in its regulation. This study was conducted to examine if the fasting-induced down-regulation of the PVN-nNOS expression is restored by activation of cAMP-dependent protein kinase A (cAMP/PKA) pathway. Freely moving rats received intracerebroventricular (icv) injection of cAMP/PKA activator Sp-cAMP (40 nmol) or vehicle (sterilized saline) following 48 h of food deprivation. One hour after drug injections, rats were transcardially perfused with 4% paraformaldehyde, and the PVN tissues were processed for nNOS or pCREB immunohistochemistry. Sp-cAMP significantly increased not only nNOS but also pCREB immunoreactivities in the PVN of food deprived rats. Fastinginduced down-regulation of the PVN-nNOS was restored by 1 h after the icv Sp-cAMP. Results suggest that cAMP/PKA pathway may mediate the regulation of the PVN-nNOS expression depending on different feeding conditions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권1호
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• pp.28-35
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• 2008

Purpose: The nitric oxide (NO) release by inducible nitric oxide synthase (iNOS) is the key events in macrophage response to lipopolysaccharide (LPS) which is suggested to be a crucial mediator for inflammatory and innate immune responses. NO is an important mediator involved in many host defense action and may also lead to a harmful host response to bacterial infection. However, given the importance of iNOS in a variety of pathophysiological conditions, control of its expression and signaling events in response to LPS has been the subject of considerable investigation. Materials and Methods: The Raw264.7 macrophage cell line was used to observe LPS-stimulated iNOS expression. The expression of iNOS is observed by Western blot analysis and real-time RT-PCR. Protein kinase C $(PKC)-{\alpha}$ overexpressing Raw264.7 cells are established to determine the involvement of $PKC-{\alpha}$ in LPS-mediated iNOS expression. $NF-{\kappa}B$ activity is measured by $I{\kappa}B{\alpha}$ degradation and $NF-{\kappa}B$ luciferase activity assay. Results: We found that various PKC isozymes regulate LPS-induced iNOS expression at the transcriptional and translational levels. The involvement of $PKC-{\alpha}$ in LPS-mediated iNOS induction was further confirmed by increased iNOS expression in $PKC-{\alpha}$ overexpressing cells. $NF-{\kappa}B$ dependent transactivation by LPS was observed and $PKC-{\alpha}$ specific inhibitory peptide abolished this activation, indicating that $NF-{\kappa}B$ activation is dependent on $PKC-{\alpha}$. Conclusion: Our data suggests that $PKC-{\alpha}$ is involved in LPS-mediated iNOS expression and that its downstream target is $NF-{\kappa}B$. Although $PKC-{\alpha}$ is a crucial mediator in the iNOS regulation, other PKC isozymes may contribute LPS-stimulated iNOS expression. This finding is needed to be elucidated in further study.

• Archives of Pharmacal Research
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• 제23권4호
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• pp.407-412
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• 2000

The presence of the nitric oxide synthase (NOS) enzyme from Salmonella typhimurium (S. typhimurium) was identified by measuring radiolabeled L-$[^3H]$citrulline and NO, and Western blot analysis. NOS was partially purified by both Mono Q ion exchange and Superose 12HR size exclusion column chromatography, sequentially. The molecular weight of NOS was estimated to be 93.3 kDa by Western blot analysis. The enzyme showed a significant dependency on the typical NOS cofactors; an apparent Km for L-arginine of 34.7 mM and maximum activity between $37^{\circ}C$ and $43^{\circ}C$. The activity was inhibited by NOS inhibitors such as aminoguanidine and $N^{G}$ $N^{G}$-dimethyl-L-arginine. taken together, partially purified NOS in S. typhimurium is assumed to be a different isoform of mammalian NOSs.OSs.

• The Korean Journal of Physiology and Pharmacology
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• 제5권4호
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• pp.343-351
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• 2001

This study was undertaken to investigate the mechanism of lipopolysaccharide (LPS) and nitric oxide (NO) as a regulator of vascular smooth muscle cell (VSMC) proliferation. VSMC was primarily cultured from rat aorta and confirmed by the immunocytochemistry with anti-smooth muscle myosin antibody. The number of viable VSMCs were counted, and lactate dehydrogenase (LDH) activity was measured to assess the degree of cell death. Concentrations of nitrite in the culture medium were measured as an indicator of NO production. LPS was introduced into the medium to induce the inducible nitric oxide synthase (iNOS) in VSMC, and Western blot for iNOS protein and RT-PCR for iNOS mRNA were performed to confirm the presence of iNOS. Inhibitors of iNOS and soluble guanylate cyclase (sGC), sodium nitroprusside (SNP) and L-arginine were employed to observe the action of LPS on the iNOS-NO-cGMP signalling pathway. LPS and SNP decreased number of VSMCs and increased the nitrite concentration in the culture medium, but there was no significant change in LDH activity. A cell permeable cGMP derivative, 8-Bromo-cGMP, decreased the number of VSMCs with no significant change in LDH activity. L-arginine, an NO substrate, alone tended to reduce cell count without affecting nitrite concentration or LDH level. Aminoguanidine, an iNOS specific inhibitor, inhibited LPS-induced reduction of cell numbers and reduced the nitrite concentration in the culture medium. LY 83583, a guanylate cyclase inhibitor, suppressed the inhibitory actions of LPS and SNP on VSMC proliferation. LPS increased amounts of iNOS protein and iNOS mRNA in a concentration-dependent manner. These results suggest that LPS inhibits the VSMC proliferation via production of NO by inducing iNOS gene expression. The cGMP which is produced by subsequent activation of guanylate cyclase would be a major mediator in the inhibitory action of iNOS-NO signalling on VSMC proliferation.

• Preventive Nutrition and Food Science
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• 제12권2호
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• pp.74-78
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• 2007

Fucoidan, that is high-molecular-weight sulfated polysaccharides extracted from brown seaweeds has been shown to elicit various biological activities. Here, we investigated the effects of fucoidan on cell proliferation and nitric oxide (NO) production in neuronal blastoma cell (SH-SY5Y). In the present study, we demonstrated that fucoidan treatment resulted in increase of cell proliferation and NO production. When cells were treated with amyloid-${\beta}$ (A${\beta}$) in the absence or presence of fucoidan, fucoidan recovered the cell viability decreased by A${\beta}$ peptides. To further determine whether nitric oxide synthase (NOS) is involved in proliferative effect of fucoidan, cells were treated with NOS inhibitors in the absence or presence of fucoidan. Selective constitutive nitric oxide synthase (cNOS) inhibitor, diphenylene iodonium chloride (DPI), caused a decrease of cell viability, whereas cell viability was increased by specific inducible nitric oxide synthase (iNOS) inhibitor, S-methylisothiourea (SMT), in the fucoidan-untreated cells. Treatment with fucoidan inhibited the cell viability decreased in DPI-exposed cells. In contrast, fucoidan had no effect on cell growth in SMT-treated cells, indicating that cNOS may not play a role in the proliferation of fucoidan-treated cells. The present data suggest that fucoidan has proliferative and neuroprotective effects and these effects may be associated with iNOS.

• 한국식품영양과학회지
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• 제36권3호
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• pp.305-310
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• 2007

복분자, 산수유 및 토사자를 일정한 비율로 배합하여 열수추출로 얻어진 KH-305를 일반쥐에 투여해서 해면체 평활근 이완에 관련된 세포 내 신호전달체계 NO-cGMP pathway에 관여하는 NOS, 혈액내의 testosterone, BVSMCs cell에서 cGMP농도를 측정하여 음경발기 지속 및 촉진에 미치는 영향을 보았으며 음경조직의 활성산소제거와 관련하여 SOD/Mn, SOD/Cu의 단백질 발현정도를 측정하였다. KH-305는 NO-pathway에 관여하는 NOS의 발현증가, 낮은 농도에서의 cGMP농도 증가, testosterone의 수치를 증가시킴으로써 발기유지 및 촉진시키고, 동시에 음경조직내의 활성산소 및 NO 합성에서 나타나는 독성을 조절하여 주는 SOD발현이 증가됨으로써 활성산소에 의한 음경피로도를 경감시켜 음경해면체 평활근의 이완장애를 일으키는 발기부전 증상을 개선시킬 것으로 생각된다.