• Journal of Environmental Science International
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• v.20 no.12
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• pp.1509-1519
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• 2011

The protective effect of nitric oxide (NO) on the antioxidant system under paraquat(PQ) stress was investigated in leaves of 8-week-old lettuce (Lactuca sativa L.) plants. PQ stress caused a decrease of leaf growth including leaf length, width and weight. Application of NO donor, sodium nitroprusside (SNP), significantly alleviated PQ stress induced growth suppression. SNP 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 PQ exposure, suggesting that NO has protective effect on chloroplast membrane in lettuce leaves. Flavonoids and anthocyanin were significantly accumulated in the leaves upon PQ exposure. However, the rapid increase of these compounds was alleviated in the SNP treated leaves. PQ treatment resulted in lipid peroxidation and induced accumulation of hydrogen peroxide ($H_2O_2$) in the leaves, while SNP prevented PQ induced increase in malondialdehyde (MDA) and $H_2O_2$. These results demonstrate that SNP serves as an 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, superoxide dismutase (SOD) and catalase (CAT) in lettuce leaves in the presence of NO donor under PQ stress were higher than those under PQ stress alone. Application of 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a specific NO scavenger, to the lettuce leaves arrested SNP mediated protective effect on leaf growth, photosynthetic pigment and antioxidant systems. However, PTIO had little effect on lettuce leaves under PQ stress compared with that of PQ stress alone. The obtained data suggest that the damage caused by PQ stress is in part due to increased generation of active oxygen by maintaining increased antioxidant enzyme activities and SNP protects plants from oxidative stress. From these results it is suggested that NO might act as a signal in activating active oxygen scavenging system that protects plants from oxidative damage induced by PQ stress and thus confer PQ tolerance.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.6
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• pp.461-467
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• 2009

The auditory cortex (A1) encodes the acquired significance of sound for the perception and interpretation of sound. Nitric oxide (NO) is a gas molecule with free radical properties that functions as a transmitter molecule and can alter neural activity without direct synaptic connections. We used whole-cell recordings under voltage clamp to investigate the effect of NO on spontaneous GABAergic synaptic transmission in mechanically isolated rat auditory cortical neurons preserving functional presynaptic nerve terminals. GABAergic spontaneous inhibitory postsynaptic currents (sIPSCs) in the A1 were completely blocked by bicuculline. The NO donor, S-nitroso-N-acetylpenicillamine (SNAP), reduced the GABAergic sIPSC frequency without affecting the mean current amplitude. The SNAP-induced inhibition of sIPSC frequency was mimicked by 8-bromoguanosine cyclic 3',5'-monophosphate, a membrane permeable cyclic-GMP analogue, and blocked by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, a specific NO scavenger. Blockade of presynaptic $K^+$ channels by 4-aminopyridine, a $K^+$ channel blocker, increased the frequencies of GABAergic sIPSCs, but did not affect the inhibitory effects of SNAP. However, blocking of presynaptic $Ca^{2+}$ channels by $Cd^{2+}$, a general voltage-dependent $Ca^{2+}$ channel blocker, decreased the frequencies of GABAergic sIPSCs, and blocked SNAP-induced reduction of sIPSC frequency. These findings suggest that NO inhibits spontaneous GABA release by activation of cGMP-dependent signaling and inhibition of presynaptic $Ca^{2+}$ channels in the presynaptic nerve terminals of A1 neurons.

• Korean Journal of Microbiology
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• v.50 no.2
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• pp.87-94
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• 2014

Nitric oxide (NO), which has been recognized as an integral molecule in maintaining homeostasis, plays an important role in host defense against microbes. NO has diverse antimicrobial mechanisms by directly and/or indirectly interacting with microbes. Under the circumstance that there is an urgent need for a new class of antimicrobial agents due to antibiotic resistance, much effort has been made to develop a NO-based antimicrobial agent. In order to make it possible, strategies to store and release NO in a controlled manner are required because NO has a gaseous property and a very short half-life. In this review, we described NO biochemistry and its mechanisms of antimicrobial activity. In additions, we introduced various NO-releasing systems that improve NO's antimicrobial activity.

• Korean Journal of Veterinary Research
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• v.36 no.3
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• pp.599-605
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• 1996

This study was designed to examine the mechanism of penile erection in adult bull by analyzing the responses of bovine proximal retractor penile muscle strips(BRP) to electtical field stimulation(EFS), exogenous nitric oxide(NO), NO synthesis precursor(L-arginine), NO synthase inhibitors(L-NAME, L-NMMA), guanylate cyclase inhibitor(methylene blue) and nonspecific potassium channel blocker(tetraethylammonium, TEA) treatments. Isometric tension of BRP was measured using physiograph. Results were summarized as follows: 1. EFS of nonadrenergic noncholinrgic(NANC) nerve in BRP produced frequency-dependent inhibitory responses to the contraction induced by co-treatment of epinephrine, guanethidine and atropine. The inhibitory responses to EFS were blocked by tetrodotoxin(TTX, $1{\mu}M$). 2. Treatment of L-NAME ($10,\;20{\mu}M$) inhibited the relaxation to EFS whereas L-NMMA ($100{\mu}M$) had no effect. 3. Treatment of NO($20,\;40{\mu}M$; as an acidified solution of $NaNO_2$) induced concentration-dependent relaxation whereas preincubation of TTX($1{\mu}M$) and L-NAME($20{\mu}M$) had no effect on the relaxation response. 4. L-arginine treatment(10mM) blocked the inhibitory effect of L-NAME($20{\mu}M$). 5. Pretreatment of methylene blue($40{\mu}M$) reduced the NANC-induced relaxation of BRP. 6. Tetraethylammonium(TEA, 80mM) reduced NANC relaxation. These results suggest that NO may act as a NANC neurotransmitter in BRP and the effects might be mediated by cGMP and potassium channel.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.3 s.58
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• pp.173-180
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• 2006

Sesame (Sesamum indicum L.), one of the oldest oilseed crops, has been known to posses antioxidative and inflammatory effects. This seed contains lignan compounds such as sesamin, sesamol, sesaminol, sesaminol diglucosides (SDG), and sesaminol triglucosides (STG). Sesamin, a major lignan in sesame, displayed several biological activities including a protective effects against oxidative damage in the skin. In the present study, we investigated the effect of sesamin, sesamol, sesaminol, SDG, and STG, on nitric oxide (NO) induction and inducible nitric oxide synthane (iNOS) and cyclooxygenases-2 (COX-2) expression in lipopolysaccharides (LPS)-treated RAW 264.7 cells. The results showed that sesamol and sesaminol significantly inhibited NO generation but they were also cytotoxicity however, sesamin effectively inhibited NO production ($IC_{50}: 64{\mu}M$) without my cytotoxic effect in LPS-stimulated macrophage RAW 264.7 cells. In further study, it was founded that sesamin inhibited the expression of inducible nitric oxide synthase but not COX-2 expression. These results suggest that sesamin may be useful for improvements of the inflammatory diseases.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.5
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• pp.1315-1321
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• 2008

Chan-Su (Venenum bufonis) has long been for a variety of other purposes including treatment of inflammation in the folk medicine recipe. Since nitric oxide (NO) is one of the major inflammatory parameters, we first studied the effects of Chan-Su on NO production in lipopolysaccharide (LPS)-stimulated BV2 microglial cells, Chan-Su inhibited the secretion of NO in BV2 microglial cells, without affecting cell viability, The protein level of inducible nitric oxide synthase (iNOS) was decreased by Chan-Su, And Chan-Su also inhibited production of prostaglandin E2 (PGE2) and expression of cyclooxygenase (COX)-2. Proinflammatory cytokines, such as tumor necrosis factor $(TNF)-{\alpha}$, interleukin $(IL)-1{\beta}$ and IL-12, were inhibited by Chan-Su in a dose-dependent manner. And Chan-Su inhibited the degradation of ${IkB-\alpha}$, which was considered to be inhibitor of nuclear factor $(NF)-{\kappa}B$, one of a potential transcription factor for the expression of iNOS, COX-2 and proinflammatory cytokines. These results suggest that Chan-Su could exert its anti-inflammatory actions by suppressing the synthesis of NO through inhibition of $I{\kappa}B-{\alpha}$ degradation.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.4
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• pp.961-966
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• 2007

Lesser yang person-Hyungbangpaedok-san (HBPDS) is a prescription originated in the

• Clinical and Experimental Pediatrics
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• v.57 no.5
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• pp.211-216
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• 2014

Asthma comprises a heterogeneous group of disorders characterized by airway inflammation, airway obstruction, and airway hyperresponsiveness (AHR). Airway inflammation, which induces AHR and recurrence of asthma, is the main pathophysiology of asthma. The fractional exhaled nitric oxide (FeNO) level is a noninvasive, reproducible measurement of eosinophilic airway inflammation that is easy to perform in young children. As airway inflammation precedes asthma attacks and airway obstruction, elevated FeNO levels may be useful as predictive markers for risk of recurrence of asthma. This review discusses FeNO measurements among early-childhood wheezing phenotypes that have been identified in large-scale longitudinal studies. These wheezing phenotypes are classified into three to six categories based on the onset and persistence of wheezing from birth to later childhood. Each phenotype has characteristic findings for atopic sensitization, lung function, AHR, or FeNO. For example, in one birth cohort study, children with asthma and persistent wheezing at 7 years had higher FeNO levels at 4 years compared to children without wheezing, which suggested that FeNO could be a predictive marker for later development of asthma. Preschool-aged children with recurrent wheezing and stringent asthma predictive indices also had higher FeNO levels in the first 4 years of life compared to children with wheezing and loose indices or children with no wheeze, suggesting that FeNO measurements may provide an additional parameter for predicting persistent wheezing in preschool children. Additional large-scale longitudinal studies are required to establish cutoff levels for FeNO as a risk factor for persistent asthma.

• The Journal of Korean Medicine
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• v.27 no.4
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• pp.74-83
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• 2006

Ssanghwatang (SHT) has been known to prove effective in the treatment for erectile dysfunction (ED), and its modified formula is widely used in clinical practice. However, its fundamental mechanism of action is not clearly known. It is well known that endothelial cells can achieve the relaxation of vascular smooth muscles by the release of nitric oxide (NO). NO is synthesized by the enzyme NO synthase (NOS) from L-arginine and oxygen. It is widely accepted that NO plays an important role in the relaxation of corpus cavernous smooth muscle and vasculature. In addition, in terms of the penile erection, the NO/cGMP pathway is more potent than the PCE1/cAMP pathway. The main purpose of the present study was to investigate the mechanism of the erectile effects of SHT by focusing on its direct effects on corpus cavernous smooth muscle cells. We investigated the NOS activity, nitrite concentration and cGMP levels in rat corpus cavernous smooth muscle cell lines activated by SHT extracts. Furthermore, we evaluated the effect of SHT extracts on penile smooth muscle relaxation following oral administration of SHT extract powder to rats by the dosage of 1 g/kg over fifteen days. As a result, we found that SHT stimulated NO release. NOS activity and cGMP levels were increased by SHT respectively. Furthermore, SHT relaxed the corpus cavernous smooth muscle. These results are consistent with the concept that penile erection by SHT is carried out through the NO/cGMP pathway. In conclusion, the present study shows that SHT increases the NOS activity, synthesizes NO and augments the cGMP, which mediates penile erection. Further determination of the SHT mechanism related with the NO/cGMP pathway strongly indicates that SHT can be used as a remedy for erectile impotence.

• Korean Journal of Acupuncture
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• v.22 no.4
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• pp.109-116
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• 2005

목적 : 골관절염은 진통을 수반하는 퇴행성 관절질환이며, 장애를 일으키는 주요한 원인이 된다. 또한 노인들에 있어서 골관절염은 매우 흔한 질환이라 할 수 있다. Nitric oxide(NO)는 Nitric Oxide Synthase(NOS)에 의하여 칼슘의존성통로를 통하여 L-arginine 으로부터 합성되어지며, NO는 중추신경계에 있어서 중요한 세포사이의 전달자이다. 방법 :본 연구에서는 위령선 으로부터 추출한 액이 콜라겐으로 유도된 관절염에 걸린 쥐의 dorsolateral periaqueductal gray(DL-PAG) 영역에서 nNOS(neuronal NOS)와 NOS에 대하여 미치는 영향 을 nNOS immunohistochemistry와 nicotinamide adenine dinucleotide phosphate-diaphorase(NADPH-d) 검사법을 통하여 조사하였다. 결과 : 골관절염이 유발된 흰쥐의 DL-PAG 영역에서 nNOS와 NOS의 발현억제가 관찰되었으며, 위령선이 콜라겐으로 유도된 골관절염에서 감소된 nNOS와 NOS의 발현이 증가되었다. 결론 : 본 연구를 통하여 위령선은 골관절염이 유발된 흰쥐의 DL-PAG에서의 nNOS와 NOS의 발현에 영향을 미친다는 결과를 얻을 수 있었다.