• 대한의생명과학회지
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• 제19권3호
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• pp.180-187
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• 2013

Hypoxia is an integral part of the environment during luteolysis. In this study we examined whether hypoxia could directly stimulate endothelial cells to produce nitric oxide (NO). Endothelial cells were cultured in hypoxic (5% $O_2$) or normoxic (20% $O_2$) conditions and the levels of total NO, inducible NO and endothelial NO was measured. We found that hypoxia but not normoxia upregulated NO production. The increased NO levels correlated with increased inducible NO synthase (iNOS) expression whereas expression of endothelial NOS (eNOS) expression remained constant. Addition of the iNOS specific inhibitor 1400W to hypoxic cultures prevented NO production suggesting that hypoxia-induced NO production in endothelial cells was due mainly to upregulation of iNOS. We also found that prostaglandin $F_{2{\alpha}}$ (PGF) production was unaffected by hypoxia suggesting that upregulation of NO was not due to increased synthesis of PGF. In summary, we report that endothelial cells cultured under hypoxic conditions produce NO via the iNOS pathway. This study provides the importance of the relation between the hypoxic environment and the induction of NO by endothelial cells during regression of the corpus luteum in the ovary.

• 대한수의학회지
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• 제43권4호
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• pp.551-554
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• 2003

Nitric oxide synthase (NOS) has been reported in uterus. We examined the expression of the NOS isoforms, constitutive endothelial (eNOS) and inducible NOS (iNOS), in bovine uterus by immunohistochemistry. eNOS immunoreactivity was localized predominantly to the endothelial cells that line uterine microvessels and to endometrial glandular epithelial cells, but was barely detectable in endometrial stromal cells. iNOS immunostaining was detected in glandular epithelial and stromal cells in the endometrium and in the endothelial cells of myometrial blood vessels. These findings suggest that both eNOS and iNOS may play important roles in the physiology of the uterus, possibly by generating NO.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 춘계학술대회 논문집
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• pp.50-50
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• 2003

Nitric oxide (NO) has been studied and found to be an important intracellular modulator. The excess NO produced by the inducible nitric-oxide synthase (iNOS) is implicated in various inflammatory diseases and cellular injury. Inflammatory cytokines such as TNF- or IL-6 increase intracellular ceramide and ceramide may induce NO production and inflammation. (omitted)

• 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.

• 약학회지
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• 제42권5호
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• pp.540-543
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• 1998

The nitric oxide (NO) produced in large amounts by inducible nitric oxide synthase is known to be responsible for the vasodilation and hypotension observed in septic shock. We have found that 8-epi-xanthatin from Xanthium strumarium L. inhibited the production of NO in LPS-activated RAW 264.7 cells ($IC_{50}$ value was 1.5 ${\mu}$M). This activity was resulted from the suppressing of inducible nitric oxide synthase enzyme expression.

• Journal of Applied Biological Chemistry
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• 제62권2호
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• pp.149-155
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• 2019

Elicitor treatment was performed to increase the anti-inflammatory activity of useful biological sources. The result showed that elicitor-treated Saururus chinensis leaf extracts positively affected nitric oxide (NO) production, and the expression of inducible NO synthase and cyclooxygenase-2 compared to extracts not exposed to elicitor treatment. This finding identified elicitor treatment as a suitable strategy for increasing the biological activity of S. chinensis. Therefore, elicitor-treated S. chinensis is useful both as health functional and medicinal materials.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.293.2-293.2
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• 2002

Bisphenol A ［BPA. 2.2-bis(4-hydroxyphenyl)propane］ is reported to have estrogenic activity: however. its influence on cytokine production or immune system function remains unclear. In this study. we investigated the effects of BPA on the production of nitric oxide (NO) and tumor necrosis factor-a (TNF-a), and on the level of inducible nitric oxide synthase (iNOS) and TNF-a gene expression in mouse macrophages. BPA alone did not affect NO or TNF-a production. (omitted)

• The Korean Journal of Physiology and Pharmacology
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• 제7권5호
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• pp.283-287
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• 2003

While nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) is beneficial for host survival, it is also detrimental to the host. Thus, regulation of iNOS gene expression may be an effective therapeutic strategy for the prevention of unwanted reactions at various pathologic conditions. During the screening process for the possible iNOS regulators, we observed that esculetin is a potent inhibitor of cytokine-induced iNOS expression. The treatment of 3T3-L1 adipocytes with the tumor necrosis factor-${\alpha}$ (TNF) induced iNOS expression, leading to enhanced NO production. TNF-induced NO production was inhibited by esculetin in a dose-dependent manner. Esculetin inhibited the TNF-induced NO production at the transcriptional level through suppression of iNOS mRNA and subsequent iNOS protein expression. These results suggest esculetin, a component of natural products, as a naturally occurring, nontoxic means to attenuate iNOS expression and NO-mediated cytotoxicity.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.176-176
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• 1998

An enhanced formation of nitric oxide (NO) is an important mediator of hypotention, peripheral vasodilation and vascular hyporeactivity to vasoconstrictor agents in endotoxaemia. And tumor necrosis factor (TNF${\alpha}$), as a primary mediator of circulatory shock has been known to induce inducible nitric oxide synthase (i-NOS), leading to excessive production of NO. We isolated two sesquiterpene lactone compounds from Saussurea lappa and their structures were elucidated as dehydrocostus lactone and costunolide. These compounds inhibit the production of both NO and TNF${\alpha}$ by LPS (1 $\mu\textrm{g}$/$m\ell$)-activated Raw 264.7 cells. NO was measured spectropho-tometrically as nitrite by the Griess reagent and TNF${\alpha}$ by ELISA. Dehydrocostus lactone (IC$\sub$50/ : 3.0 ${\mu}$M) and costunolide (IC$\sub$50/ : 4.5 ${\mu}$M) inhibited the production of NO in LPS-activated Raw 264.7 cells by suppressing inducible nitric oxide synthase enzyme expression. These compounds also decreased the TNF${\alpha}$ levels in LPS-activated system in vitro and in vivo.

• Asian-Australasian Journal of Animal Sciences
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• 제22권7호
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• pp.1048-1053
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• 2009

The present study was conducted to determine the effects of chitosan on nitric oxide (NO) content and inducible nitric oxide synthase (iNOS) activity in serum, and relative expression of iNOS mRNA in the duodenum, jejunum, and ileum of broiler chickens. A total of 240 one-day-old Arbor Acre mixed-sex broiler chickens were randomly allotted to six dietary treatments with five replicates in each treatment and eight chickens in each replicate. The broiler chickens in the six treatments were fed the basal diet supplemented with 0 (control), 0.05, 0.2, 0.5, 1.0 or 2.0 g/kg chitosan. The trial lasted for 42 days. The results showed that dietary chitosan enhanced NO content and iNOS activity in serum as well as iNOS mRNA expression in the duodenum and ileum of broiler chickens in a quadratic dose-dependent manner (p<0.05), and improved jejunum iNOS mRNA expression in a quadratic dose-dependent manner (p<0.10) with increasing addition of chitosan. Chicks fed a diet containing 0.5-1.0 g/kg chitosan had higher NO content and iNOS activity in serum as well as small-intestinal iNOS mRNA expression compared with birds given the control diet, but positive effects of chitosan tended to be suppressed when addition of chitosan in the diet was increased to 2.0 g/kg. These results implied that there was a threshold level of chitosan inclusion beyond which progressive reductions in serum NO content and small intestinal iNOS expression occured, and the regulation of chitosan on immune functions in chickens is probably associated with activated expression of iNOS and NO secretion.