• The Korean Journal of Physiology and Pharmacology
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• v.20 no.5
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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.

• Korean Journal of Pharmacognosy
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• v.35 no.4 s.139
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• pp.283-287
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• 2004

The effect of water extract from Cnidii Rhizoma (CRW) on proliferation of human breast cancer cells, nitric oxide production, nitric oxide synthase expression, and ornithine decarboxylase activity was tested. CRW inhibited the growth of both estrogen-dependent MCF-7 and estrogen-independent MDA-MB-23I human breast cancer cells. Lipopolysaccharide-induced nitric oxide (NO) production was significantly reduced by CRW at the concentration of 0.5, 1.0 and 5.0 mg/ml. Expression of inducible nitric oxide synthase (iNOS) was also suppressed with the treatment of CRW in Raw 264.7 cells. CRW inhibited induction of ornithine decarboxylase by 12-0-tetradecanoylphorbol-13-acetate, a key enzyme of polyamine biosynthesis, which is enhanced in tumour promotion. Therefore, CRW is worth further investigation with respect to breast cancer chemoprevention or therapy.

• YAKHAK HOEJI
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• v.38 no.1
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• pp.24-30
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• 1994

Nitric oxide(NO) synthase was identified and characterized by determining the L-citrulline formed in the NO-Arg pathway in pancreatic tissues. NO synthase activities in chicken pancreas were dependent upon the concentration of L-Arg which is the substrate molecule for the NO synthase, the amount of the enzyme protein used, and linearly on the incubation time. NO synthase in mouse pancreas was found to be constitutive, not induced by lipopolysaccharide treatment. In vitro NO synthase activities of chicken pancreas were inhibited 36%, 21%, 12% and 44% by $200\;{\mu}M$ of MMA, DMA, D'MA and NAME respectively. These results suggest the presence of NO and NO synthase in the pancreas.

• Journal of Acupuncture Research
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• v.23 no.4
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• pp.115-121
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• 2006

Objectives : This study was designed to investigate the scavenging effect on Nitric Oxide of BUM. Methods : The scavenging effect on NO concentrations 2, 6, 12 and 24 hours after treatment with Vit C. and BUM at 1, 10, $100{\mu}g/ml$ were estimated. And those was compared with control group. Results : 1. The concentration of NO 2 hours after treatment with BUM at 1, 10, 1$100{\mu}g/ml$ were decreased compared with control group. 2. The conecntration of NO 6 hours after treatment with BUM at 1, 10, 1$100{\mu}g/ml$ were decreased compared with control group. 3. The concentration of NO 12 hours after treatment with BUM at 1, 10, $100{\mu}g/ml$ were decreased compared with control group. 4. The concentration of NO 24 hours after treatment with BUM at 1, $100{\mu}g/ml$ were decreased compared with control group. Conclusion : The scavenging effect of BUM on NO was dose-dependent.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.185-185
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• 1996

Nitric oxide synthase(NO Synthase:E.C.1.14.13.39)는 생체내에서 L-arginine을 기질로 하여 citrulline과 nitric oxide(NO)를 생성하는 효소로서, 최근 연구에 의하면 2/3 부분 간 절제술 후 prereplicative phase동안에 발현되는 것으로 알려져 있다. 한편, 생체내에서 NO Synthase에 상경적 길항제인 methylarginine에 관해서도 수년간 많은 연구가 진행되어 왔다. 이들의 생성 기전은 protein methylation에 의해 생성된 methylated protein이 생체 내에서 분해되어 생성된다고 알려져 있으나, 정확한 기전에 대해서는 아직 논란의 여지가 많다. 따라서, 본 연구에서는 In vivo 실험을 통해 부분 간 절제술 후 시간대별로 간 조직에서의 NO Synthase 활성도와 혈청에서 NO의 최종 대사물인 Nitrite/Nitrate를 측정하였으며, 또한 NO Synthase 조절에 관여하는 세포내 기질인 arginine과 억제 인자인 methylarginine함량을 간 조직 및 혈청에서 측정하고, 세포 신호 전달체계에 관여하는 cyclic GMP 함량을 측정함으로써, 부분 간 절제술 후 간 재생동안에 NO Synthase 활성도와 methylarginine 및 arginine과의 상관 관계를 규명하고, 간 재생동안, 생성된 nitric oxide의 역할을 연구하려한다.

• Journal of Acupuncture Research
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• v.24 no.4
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• pp.99-105
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• 2007

목적 : 본 연구는 최근 임상에서 많이 사용하는 자하거 약침액의 nitric oxide(NO)에 대한 소거 효과를 분석하기 위하여 실행되었다. 방법 : 양성대조군으로 비타민C와 실험군으로 자하거 약침액에 NO를 분비하는 S-nitroso-N-acetylpenicillamine(SNAP)을 투여한 후 NO의 농도를 540nm 파장의 자외선 흡수량을 측정하여 평가하였다. 결과 : 실험에 사용된 자하거 약침액의 NO 소거 효과는 강력한 항산화제인 비타민C보다 우수하지는 못하였으나 0.005 및 0.001mg/ml 농도에서 12시간 동안 SNAP를 투여한 후 생성된 NO를 유의성 있게 소거하는 효과가 나타났다. 결론 : 이상의 결과를 통하여 자하거 약침액이 NO를 소거하는 효과가 있는 것이 확인이 되었으나 추후 농도별 실험과 다른 시료와의 비교실험이 더 요구된다.

• Journal of Integrative Natural Science
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• v.1 no.1
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• pp.41-46
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• 2008

The aim of this study is to evaluate the effects essential oil from Lavendular officinalis on the production of UVB-irradiated-induced nitric oxide(NO), in vivo and in vitro. NO is a recently discovered mediator of cell communication involved in a variety of physiological and pathophysiological processes. This enzyme is present in various tissues including smooth muscle cells and macrophages and take part in several immunopathological process. In vitro, the cytotoxicity and cell viability of aroma oil was evaluated by the MTT assay in the concentration of 0.01, 0.05, 0.1%. And, the effect of aroma oil was investigated to production of NO in human fibroblast cells line CCD-986sk ($2{\times}10^5$ cell/well) after UVB-irradiation with aroma oil (0.01, 0.1, and 1%). The result showed that aroma oil did not affected the production of NO. In vivo, it was investigated to production of NO after UVB- irradiation with aroma oil. The experimental groups were divided into four groups. Aroma oil was stimulated the production of NO by itself. As the results, all of the in vitro and in vivo, aroma oil were affected production of NO by dependent the concentration-manners.

• Journal of Life Science
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• v.21 no.4
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• pp.534-541
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• 2011

Retinoic acid (RA), a metabolite of vitamin A, is known to regulate dedifferentiation of rabbit articular chondrocytes. The regulatory mechanism of dedifferentiation by RA is not yet understood. Thus, the effect of RA on the regulation of nitric oxide (NO)-induced dedifferentiation was investigated in rabbit articular chondrocytes. RA caused loss of the differentiated chondrocyte phenotype as demonstrated by inhibition of type II collagen expression and proteoglycan synthesis. RA also accelerated NO-induced dedifferentiation in rabbit articular chondrocytes as detected by expression of type II collagen and Sox-9 using Western blot analysis and production of sulfated proteoglycan using Alcain blue staining. Further, RA potentiated NO-induced activation of ERK. Inhibition of ERK with PD98059 (PD) recovered the expression of type II collagen and Sox-9 and production of sulfate proteoglycan in NO-induced dedifferentiated chondrocytes by RA treatment. Our findings suggest that RA accelerates NO-induced dedifferentiation of rabbit articular chondrocytes via the ERK pathway.

• Korean Journal of Plant Resources
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• v.32 no.4
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• pp.264-269
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• 2019

This research was performed to identify the anti-inflammatory constituent from the herb of Lycorus lucidus (Lamiaceae). The MeOH extract of this plant material and its two fractions, the lipophilic- ($CHCl_3$ fraction) and the hydrophilic fraction (BuOH fraction), were prepared to test anti-inflammatory activity. For this purpose, the inhibition rate on inducible nitric oxide synthase (iNOS) activity was assessed by determining nitric oxide (NO) formation in lipopolysaccharide (LPS)-induced macrophage 264.7 cells. The $CHCl_3$ fraction that greatly inhibited nitric NO formation was chromatographed to lead the isolation of ursolic acid. Since ursolic acid inhibited NO formation dose dependently in this study, this compound was considered as one of the active constituent responsible for anti-inflammation. However, the activity of rosmarinic acid isolated from the BuOH fraction was weak.

• The Korean Journal of Pharmacology
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• v.30 no.3
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• pp.337-342
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• 1994

It is well known that angiotensin converting enzyme inhibitors(ACEIs) increase endothelium-dependent relaxation in aortic strips of spontaneously hypertensive rats(SHR) and this increase in relaxation may be due to altered endothelial nitric oxide breakdown. But there are few studies on the effect of the angiotensin II receptor blocker on the nitric oxide-mediated relaxation. So we attempted to investigate the effect of angiotensin II receptor blocker on the nitric oxide-dependent relaxation in isolated aorta of SHR. Two week-treatment of losartan (30 mg/kg/day) increased the acetylcholine$(10^{-9}\;to\;10^{-5}\;M)$-and histamine$(10^{-8}\;to\;10^{-4}\;M)$-induced relaxation in endothelium intact strips but 90 minutes-treatment of losartan $(10^{-4}\;M)$ showed no increase in relaxation. The phenylephrine $(10^{-7}\;M)$-induced contraction, repeated every 2 hours, was diminished gradually following lipopolysaccharide (LPS)-treatment $(100\;{\mu}g/ml)$ but there was no significant difference in enalapril- and losartan-treated group compared with control group. These results suggest that activity of the endothelial constitutive NO synthase may be changed by chronic treatment of angiotensin II receptor blockers and ACEIs but angiotensin II antagonist and ACEI have no effect on the inducible NO synthase activity in the isolated aorta of SHR