• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.4
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• pp.483-490
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• 2015

The purpose of this study was to investigate the effects of 50% ethanol extracts of ripe black raspberry (Rubus occidentalis, RBR) on hypertension in spontaneously hypertensive rats (SHR). The final systolic blood pressure of the group treated with RBR for 12 weeks was significantly lower than that of the SHR group. The mRNA expression level of endothelial nitric oxide synthase (eNOS) was significantly decreased in SHR. However, treatment with RBR and captopril increased the level of eNOS mRNA in SHR. Moreover, plasma levels of homocysteine and plasminogen activator inhibitor-1 were significantly reduced by RBR. Plasma total cholesterol, high-density lipoprotein, and low-density lipoprotein cholesterol levels were lower in SHR than Wistar Kyoto rats (WKY). However, there was no significant difference in plasma triglyceride level between WKY and SHR. The number of eosinophilic cardiac muscle cells was reduced in heart muscles after treatment with captopril and RBR. Therefore, this study suggests that RBR extracts may be useful for improvement of hypertension.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.2
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• pp.389-396
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• 2002

In the present work, we examined the mechanism of vasorelaxant effect of scopoletin, an active constituent of Artemisia capillaris on rat thoracic descending aortic rings. Scopoletin induced a concentration-dependent relaxation in rat thoracic descending aortic rings pre-contracted with phenylephrine (EC/sub 50/ = 238.94±37.4 μM), while it was less effective in rat thoracic descending aortic rings precontracted with high potassium solution (KCI 30 mM). Vasorelaxation by scopoletin was significantly inhibited after endothelial removal, but recovered at high concentration. Pretreatment of rat thoracic descending aortic rings with N/sup G/-nitro-L-arginine (100 μM), a nitric oxide synthase inhibitor, and atropine (1 μM), a muscarinic receptor antagonist, significantly inhibited scopoletin-induced relaxation of rat thoracic descending aortic rings. Neither indomethacin (3 μM), an inhibitor of cydooxygenase, nor propranolol (1 μM), a β -adrenoceptor antagonist, modified the effect of scopoletin. The combination of N/sup G/ -nitro-L-arginine (100 μ M) and miconazole (10 μ M), an inhibitor of cytochrome P 450, did not modify the effect of scopoletin, when compared with pretreatment with N/sup G/-nitro-L-arginine(100 μM) alone. Vasorelaxant effect of scopoletin was inverted by pretreatment with diltiazem (10 μM), a Ca/sup 2+/-channel blocker, at low concentration, while restored at high concentration. Apamin (K/sub ca/-channel blocker, 1 μM), 4-aminopyridine (4-AP, K/sub v/-channel blocker, 1 mM), and tetrodotoxin (TTX, Na/sup +/-channel blocker 1 μM) potentiated the vasorelaxant effect of scopoledn, but glibendamide (K/sub ATP/-channel blocker, 10 μM), tetraetylammonium(TEA, non-selective K-channel blocker, 10 mM) did not affect the relaxation of scopoletin. Free radical scavengers (TEMPO, catalase, mannitol) did not modify vascular tone. These results suggest that nitric oxide, Ca/sup 2+/ -channels play a role in endothelium-dependent relaxations to scopoletin in rat aortas, that apamin, 4-AP, TTX but not glibenclamide, TEA potentiated relaxation to scopoletin mediated by these channels, and that free radicals do not concern to the vasorelaxant effect of scopoletin.

• YAKHAK HOEJI
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• v.41 no.3
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• pp.370-380
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• 1997

The role of nitric oxide (NO) on the non-adrenergic non-cholinergic (NANC) relaxations induced by the short and prolonged electrical field stimulation (EFS) has been studied in the rabbit corpus cavernosum. In the presence of atropine and guanethidine the prolonged EFS (2-16 Hz) of corpus cavernosal strips precontracted with phenylephrine produced frequency-dependent relaxations, which were abolished by tetrodotoxin as shown in the relaxations induced gy the short EFS, indicating that their orgin is NANC nerve stimulation. $N^G$-nitro-L-arginine (L-NNA), inhibitor of nitirc oxide synthase, caused a concentration-dependent inhibition to the NANC relaxation, and at 100 M L-NNA the relaxation were virtually abolished. The inhibitory effect of L-NNA was reversed by L-arginine. Hemoglobin abolished the relaxations to NO and also caused a concentration-dependent inhibition of the NANC relaxation. The hemoglobin-resistant relaxation induced by EFS was eliminated by L-NNA. Methylene blue significantly reduced the NANC relaxation in a conentration-dependent manner. The NANC relaxation was not affected by a VIP-inactivating pepridase, alpha0chymotrypsin, whereas VIP-induced relaxation was completely abolished. NO- and VIP-induced relaxation were not affected by L-NNA. These results indicate that the NANC relaxation induced by prolonged EFS of the rabbit corpus cavernosum is mediated by NO-guanosine 3',5'-cyclic monophosphate pathway as shown in the relaxation induced by the short EFS, and that VIP release is not essential for the NANC relaxation of the rabbit corpus cavernosum and VIP is not involved the generation fo NO.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.420-433
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• 1996

Background : There have been many debates about the effects of nitric oxide on the neurogenic inflammation. The role of nitric oxide in the neurogenic inflammation of airways will be required a better understanding of the localization and types of nitirc oxide synthase(NOS) activity in the neurogenic inflammation of airways. Method : To investigate the role of nitric oxide in airway neurogenic inflammation, 1) the effects of neurokinin receptor antagonist (FK224) and nitric oxide synthase inhibitor, $N^{\omega}$-nitro-L-arginine (L-NNA) on plasma extravastion were evaluated in four groups of Sprague-Dawley rats ; sham operation group(sham NANC group), electrical vagal stimulation group(NANC2 group), intravenous pretreatment groups with FK224 (1mg/kg ; FK224 group), and L-NNA(1mg/kg ; L-NNA group) 15 minutes before vagal NANC stimulation. 2) NOS activity in trachea with neurogenic inflammation was localized by immunohistochemical stain. Immunohistochemical stain was performed by antibodies specific for inflammatory cells(iNOS), brain(bNOS), and endothelium (eNOS) on trachea obtained from sham NANC, NANC2, and FK224 groups. Results : The results are that plasma extravsation in neurogenic inflammation of rat airways was inhibited by FK224, but enhanced by L-NNA pretreatment(P<0.05). There was significantly increased infiltration of inflammatory cells in subepithelium of neurogenic inflammatory trachea, but the reduction of subepithelial infiltration of inflammatory cells was observed after pretreatment with FK224(P<0.05). Immunostaining with anti-iNOS antibody showed strong reactivity only in infiltrated inflammatory cells in neurogenic rat trachea, and these iNOS reactivity was reduced by pretreatment with FK224. bNOS immunoreactivity was significantly increased only in the nerves both of neurogenic inflammatory and FK224 pretreated trachea compared with sham NANC trachea(p<0.05). eNOS immunoreactivity was not significant change in endothelium in neurogenic inflammation of rat trachea. Conclusion : These results suggest that nitric oxide released from iNOS in infiltrated inflammatory cells has main role in neurogenic inflammation of rat trachea. The presence of bNOS immunoreactivity in the nerves indicates that nitric oxide may be released from the nerves in rat trachea with neurogenic inflammation.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.1
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• pp.25-32
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• 2014

Nitric oxide (NO) is recognized as a mediator and regulator of inflammatory responses. NO is produced by nitric oxide synthase (NOS), and NOS is abundantly expressed in the human dental pulp cells (HDPCs). NO produced by NOS can be cytotoxic at higher concentrations to HDPCs. However, the mechanism by which this cytotoxic pathway is activated in cells exposed to NO is not known. The purpose of this study was to elucidate the NO-induced cytotoxic mechanism in HDPCs. Sodium nitroprusside (SNP), a NO donor, reduced the viability of HDPCs in a dose- and time-dependent manner. We investigated the in vitro effects of nitric oxide on apoptosis of cultured HDPCs. Cells showed typical apoptotic morphology after exposure to SNP. Besides, the number of Annexin V positive cells was increased among the SNP-treated HDPCs. SNP enhanced the production of reactive oxygen species (ROS), and N-acetylcysteine (NAC) ameliorated the decrement of cell viability induced by SNP. However, a soluble guanylate cyclase inhibitor (ODQ) did not inhibited the decrement of cell viability induced by SNP. SNP increased cytochrome c release from the mitochondria to the cytosol and the ratio of Bax/Bcl-2 expression levels. Moreover, SNP-treated HDPCs elevated activities of caspase-3 and caspase-9. While pretreatment with inhibitors of caspase (z-VAD-fmk, z-DEVD-fmk) reversed the NO-induced apoptosis of HDPCs. From these results, it can be suggested that NO induces apoptosis of HDPCs through the mitochondria-dependent pathway mediated by ROS and Bcl-2 family, but not by the cyclic GMP pathway.

• Biomedical Science Letters
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• v.5 no.1
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• pp.85-93
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• 1999

Nitric oxide (NO) plays an important role in immunologic defense, and influences upon the functioning of secretory tissues and cells. It also exhibits cytotoxic/cytostatic activity as one of major operating effectors of the cellular immunity system. We investigated the effects of serum on the cell damages and NO production in the mouse liver cell line BNL CL.2 to establish the role of NO. We observed that, when BNL CL.2 cells were cultured in serum-free medium, they were induced to cell damage by the stimulation of IFN-$\gamma$ alone or IFN-$\gamma$ plus LPS. Serum-starved cells showed large amount of nitrite accumulation and NO synthase (NOS) expression in response to IFN-$\gamma$ alone in dose- and time- dependent manners, but serum-supplied cells did not The production of NO was blocked by protein tyrosine kinase (PTK) inhibitors, genistein and herbimycin. These results suggest that the deprivation of serum in the BNL CL.2 cell culture medium might primed with the cells to produce NO when the cells are triggered by IFN-$\gamma$ and the involvement of PTK signal transduction pathway in the expression of NOS gene in murine hepatocytes.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.697-703
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• 2002

We investigated that the role of nitric oxide (NO) on ischemic rats in brain and heart. Ischemia was induced by both common carotid arteries (CCA) occlusion for 24h following reperfusion. Then tissue samples were removed and measured NOx. In brain, NOx was increased by about 40% vs. normal and it was significantly inhibited by aminoguanidine, selective iNOS inhibitor. This result showed that NOx concentration was increased by iNOS. We investigated the role of $Ca^{2+}$ during ischemia. Nimodipine, L-type calcium channel blocker, didn't inhibit the increases of NOx concentration during ischemia. It suggested that increased NOx was due to calcium-independent NOS. MK-801, which N-methyl-D-aspartate (NMDA) receptor antagonist, didn't significantly prevent the increases of NOx. In heart, ischemia caused NOx decrease and it is inconsistent with NOx increase in brain. Aminoguanidine and nimodipine didnt affect on NOx decrease. But MK-801 more lowered NOx concentration than those of ischemia control group. It seemed that $Ca^{2+}$ influx in heart partially occurred via NMDA receptor and inhibited by NMDA receptor antagonist. The mean arterial pressure (MAP) in ischemic rats after 24h of CCA occlusion was decreased when compared to normal value, whereas the heart rates (HR) was not different between two groups. Aminoguanidine or MK801 had no effect on MAP or HR, but nimodipine reduced MAP. There was no difference the effects of aminoguanidine, nimodipine, or MK-801, on MAP and HR between normal rats and ischemic rats. In summary, ischemic model caused an increase of NOx concentration, suggesting that this may be produced via iNOS, which is calcium independent in brain. However in heart, ischemia decreased NOx concentration and NMDA receptor was partially involved. The basal MAP was decreased in ischemic rats but HR was not different from normal control, suggesting that increased NOx in brain of ischemic rat may result in the hypotension.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.657-663
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• 1998

The enzyme responsible for the synthesis of nitric oxide (NO) from L-arginine in mammalian tissues is known as nitric oxide synthase (NOS) (EC.1.14.13.39). In the present study, the role of NO in the regulation of exocrine secretion was investigated in rat pancreatic acinar cells. Treatment of rat pancreatic acinar cells with cholecystokinin-octapeptide (CCK-OP) resulted in an increase in the arginine conversion to citrulline, the amount of $NO_X$, the release of amylase, and the level of CGMP. Especially, CCK-OP-stimulated increase of arginine to citrulline transformation, the amount of $NO_X$, and CGMP level were completely counteracted by the inhibitor of NOS, NG-monomethyl-L-arginine (MMA), by contrast, that of amylase release was partially reduced. Furthermore, MMA-induced decrease of NOS activity and amylase release showed dose-dependent pattern. The data on the time course of CCK-OP-induced citrulline formation and CGMP rise indicate that NOS and guanylate cyclase were activated by treatment of CCK-OP. However, the mechanism of agonist-stimulated guanylate cyclase activation in acinar cells remains unknown. Therefore, activation of NOS is one of the early events in receptor-mediated cascade of reactions in pancreatic acinar cells and NO, not completely, but partially mediate pancreatic enzyme exocrine secretion.

• CELLMED
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• v.2 no.3
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• pp.27.1-27.6
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• 2012

Red ginseng, which has a variety of biological and pharmacological activities including antioxidant, anti-inflammatory, antimutagenic and anticarcinogenic effects, has been used for thousands of years as a general tonic in traditional oriental medicine. Here, we tested the immune regulatory activities of hydrolyzed red ginseng by malted barley (HRG) on the expressions of receptor interacting proteins (Rip) 2 and $I{\kappa}B$ kinase-beta (IKK-${\beta}$) in mouse peritoneal macrophages. We show that HRG increased the activations of Rip 2 and IKK-${\beta}$ for the first time. When HRG was used in combination with recombinant interferon-${\gamma}$ (rIFN-${\gamma}$), there was a marked cooperative induction of nitric oxide (NO) production. The increased expression of inducible NO synthase from rIFN-${\gamma}$ plus HRG-stimulated cells was almost completely inhibited by pre-treatment with pyrrolidine dithiocarbamate (PDTC), an inhibitor of nuclear factor-${\kappa}B$ (NF-${\kappa}B$). In addition, the treatment of peritoneal macrophages with rIFN-${\gamma}$ plus HRG caused significant increases in tumor necrosis factor (TNF)-${\alpha}$ mRNA expression and production. Because NO and TNF-${\alpha}$ play an important role in the immune function and host defense, HRG treatment can modulate several aspects of the host defense mechanisms as a result of the stimulations of the inducible nitric oxide synthase and NF-${\kappa}B$. In conclusion, our findings demonstrate that HRG increases the productions of NO and TNF-${\alpha}$ from rIFN-${\gamma}$-primed macrophages and suggest that Rip2/IKK-${\beta}$ plays a critical role in mediating these immune regulatory effects of HRG.

• Biomolecules & Therapeutics
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• v.17 no.3
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• pp.276-281
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• 2009

Lactic acid bacteria (LAB) are considered as probiotics with immunostimulatory property. In this study, we investigated the molecular mechanism of its immunostimulating potency on macrophages using combined preparation of LAB (cpLAB). cpLAB is able to strongly stimulate nitric oxide (NO) production as well as inducible NO synthase (iNOS) expression from macrophage-like RAW264.7 cells. The cpLAB-induced NO release seemed to be mediated by extracellular signal-regulated kinase (ERK) but not p38 and C-Jun N-terminal kinase (JNK), since U0126, an ERK inhibitor, clearly suppressed NO production. cpLAB significantly diminished the binding of toll like receptor (TLR)-2 antibody up to 25%, implying that cpLAB-mediated activation of macrophages may be required for the functional activation of TLR-2, but not TLR-4. Therefore, our data suggest that cpLAB may directly allow macrophages to immunostimulating potency via activation of TLR-2 and ERK.