• 한국임상수의학회지
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• 제21권3호
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• pp.236-242
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• 2004

1,2-benzopyrone can stimulate macrophages to increase the ability of phagocytosis. Peripheral blood polymorphonuclear cells (PMN) and macrophages destroy microbial organisms with reactive oxygen species (ROS), called oxidative burst activity (OBA). This study was undertaken to determine whether 1,2-benzopyrone affects the OBA on the phagocytic response of canine peripheral blood phagocytes. The OBA of phagocytes in the addition or absence of latex beads was analyzed by flow cytometry system using dihydrorhodamine 123 (DHR). The direct treatments of 1,2-benzopyrone have no effect on the OBA of peripheral blood mononuclear cells (PBMC), PMN and monocyte-rich cells regardless of addition of latex beads. When latex beads are added to PMN, the OBA of PMN was remarkably enhanced by culture supernatant from PBMC but not PMN treated with 1,2-benzopyrone. Similary, it was also enhanced by human recombinant (hr) $TNF-\alpha.$ However, when latex beads were not added to PMN, its OBA was not enhanced by culture supernatant from either PBMC or PMN treated with 1,2-benzopyrone. The OBA of latex beads-phagocytized PBMC and monocyte-rich cells was not enhanced by culture supernatant from either PBMC or PMN treated with 1,2-benzopyrone. These results strongly suggested that 1,2-benzopyrone has an immunoenhancing effect on the OBA of PMN when phagocytic response occurred only. This enhanced OBA may be mediated through active humoral substance(s), such as $TNF-\alpha,$ produced by PBMC stimulated with 1,2-benzopyrone.

• 한국식품영양학회지
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• 제11권1호
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• pp.107-113
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• 1998

홍삼의 추출물인 50% ethanol extract, crude saponin, 그리고 lipid soluble fraction이 마우스 대식세포의 oxidative burst를 유발할 수 있는지 여부를 알아보고자 in vitro와 in vivo에 각각의 추출물을 처치하고 hydrogen peroxide 생산을 DCFH-DA를 이용한 형광분광광도법으로 측정하였다. 형광분광법에 의한 hydrogen peroxide의 측정을 최적화하기 위한 DCFH-DA의 농도는 3.2$mu extrm{m}$이었고, oxidative burst를 유도하기 위한 zymosan A, PNA의 최적 농도는 각각 100$\mu\textrm{g}$, 250'기호'를 사용하였다. In vitro의 경우, 홍삼의 3가지 추출물은 모두 oxidative burst를 유발하지 못하였지만, zymosan A로 유발한 경우에는 50% ethanol extract에서 가장 높은 hydrogen peroxide를 생산하였다. In vivo 실험에서는, lipid soluble extract에서만 유의하게 증가한(P<0.01) oxidative burst를 유발하였고, ginsenoside(saponin)가 어느 정도 포함되어 있는 50% ethanol extract와 crude saponin은 대조군에 배하여 유의하게 낮은(P<0.05) hydrogen peroxide를 생산하였다. 이는 ginsenoside가 마우스의 nitric oxide 생산을 억제한다는 다른 연구자들의 보고와 일치하는 결과이다. Oxidative burst를 유발한 lipid soluble extract에는 phenol계 화합물, polyactylence계 화합물, 미량성분 등이 함유되어 있으므로 차후 연구를 통하여 과연 어느 성분이 hydrogen peroxide를 증가시키는지 규명하는 것이 필요하다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.64.1-64
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• 2003

Inoculation of primary pepper leaves with an avirulent strain of Xanthomonas campestris pv. vesicatoria induced systemic acquired resistance (SAR) in secondary leaves. This SAR response was accompanied by the systemic expression of defense-related genes, a systemic microoxidative burst generating H2O2, and the systemic induction of ion-leakage and callose deposition in the non-inoculated, secondary leaves. Some defense-related genes encoding PR-1, chitinase, peroxidase, PR10, thionin, defensin and zinc-finger protein were distiilctly induced in the systemic leaves. The systemically striking accumulation of H$_2$O$_2$and strong increase in peroxidase activity in pepper was suggested to contribute to the triggering of cell death In the systemic micro-HRs, leading to the induction of SAR. Treatment of non-inoculated, secondary leaves with diphenylene iodinium (DPI), an inhibitor of the oxidative burst, substantially reduced the induction of some defense-related genes and subsequently SAR.

• The Korean Journal of Physiology and Pharmacology
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• 제2권5호
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• pp.617-628
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• 1998

In order to understand the pathogenetic mechanism of adult respiratory distress syndrome (ARDS), the role of phospholipase A2 (PLA2) in association with oxidative stress was investigated in rats. $Interleukin-1{\alpha}\;(IL-1,\;50\;{\mu}g/rat)$ was used to induce acute lung injury by neutrophilic respiratory burst. Five hours after IL-1 insufflation into trachea, microvascular integrity was disrupted, and protein leakage into the alveolar lumen was followed. An infiltration of neutrophils was clearly observed after IL-1 treatment. It was the origin of the generation of oxygen radicals causing oxidative stress in the lung. IL-1 increased tumor necrosis factor (TNF) and cytokine-induced neutrophil chemoattractant (CINC) in the bronchoalveolar lavage fluid, but mepacrine, a PLA2 inhibitor, did not change the levels of these cytokines. Although IL-1 increased PLA2 activity time-dependently, mepacrine inhibited the activity almost completely. Activation of PLA2 elevated leukotriene C4 and B4 (LTC4 and LTB4), and 6-keto-prostaglandin $F2{\alpha}\;(6-keto-PGF2{\alpha})$ was consumed completely by respiratory burst induced by IL-1. Mepacrine did not alter these changes in the contents of lipid mediators. To estimate the functional changes of alveolar barrier during the oxidative stress, quantitative changes of pulmonary surfactant, activity of gamma glutamyltransferase (GGT), and ultrastructural changes were examined. IL-1 increased the level of phospholipid in the bronchoalveolar lavage (BAL) fluid, which seemed to be caused by abnormal, pathological release of lamellar bodies into the alveolar lumen. Mepacrine recovered the amount of surfactant up to control level. IL-1 decreased GGT activity, while mepacrine restored it. In ultrastructural study, when treated with IL-1, marked necroses of endothelial cells and type II pneumocytes were observed, while mepacrine inhibited these pathological changes. In histochemical electron microscopy, increased generation of oxidants was identified around neutrophils and in the cytoplasm of type II pneumocytes. Mepacrine reduced the generation of oxidants in the tissue produced by neutrophilic respiratory burst. In immunoelectron microscopic study, PLA2 was identified in the cytoplasm of the type II pneumocytes after IL-1 treatment, but mepacrine diminished PLA2 particles in the cytoplasm of the type II pneumocyte. Based on these experimental results, it is suggested that PLA2 plays a pivotal role in inducing acute lung injury mediated by IL-1 through the oxidative stress by neutrophils. By causing endothelial damage, functional changes of pulmonary surfactant and alveolar type I pneumocyte, oxidative stress disrupts microvascular integrity and alveolar barrier.

• 한국임상수의학회지
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• 제23권4권
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• pp.393-399
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• 2006

전신마취제인 케타민은 흥분성 아미노산의 활성을 방해하는 N-methyl-D-aspartate (NMDA) 수용체의 비경쟁적인 길항제이다. 본 연구는 개 말초혈액 백혈구의 순간산소과소비현상(Oxidative burst activity; OBA)에 있어서 케타민의 효과를 검토하였다. 탐식세포의 OBA는 유세포 분석기로 분석하였다. 케타민을 말초혈액 다형핵백혈구(peripheral blood polymorphonuclear cells; PMN)와 monocyte-rich cells에 직접처리 하였을 때는 OBA가 감소하였으며, 또한 케타민을 처리한 말초혈액 단핵구세포(peripheral blood mononuclear cells; PBMC) 배양상층액에 의해서도 PMN과 monocyte-rich cells의 OBA가 감소하였다. 그러나 케타민을 처리한 PMN 배양상층액에 의해서는 탐식세포의 OBA에 있어서 아무런 변화가 없었다. 하지만 이러한 OBA의 감소는 latex beads를 넣어 탐식반응이 일어날 때만 측정되었다. 이상의 결과로부터 탐식반응이 일어나는 동안 케타민은 호중구와 단핵구와 같은 개 말초혈액 탐식구의 OBA에 있어 억제효과를 나타내었다.

• Molecules and Cells
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• 제39권5호
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• pp.426-438
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• 2016

Plant disease resistance occurs as a hypersensitive response (HR) at the site of attempted pathogen invasion. This specific event is initiated in response to recognition of pathogen-associated molecular pattern (PAMP) and subsequent PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). Both PTI and ETI mechanisms are tightly connected with reactive oxygen species (ROS) production and disease resistance that involves distinct biphasic ROS production as one of its pivotal plant immune responses. This unique oxidative burst is strongly dependent on the resistant cultivars because a monophasic ROS burst is a hallmark of the susceptible cultivars. However, the cause of the differential ROS burst remains unknown. In the study here, we revealed the plausible underlying mechanism of the differential ROS burst through functional understanding of the Magnaporthe oryzae (M. oryzae) AVR effector, AVR-Pii. We performed yeast two-hybrid (Y2H) screening using AVR-Pii as bait and isolated rice NADP-malic enzyme2 (Os-NADP-ME2) as the rice target protein. To our surprise, deletion of the rice Os-NADP-ME2 gene in a resistant rice cultivar disrupted innate immunity against the rice blast fungus. Malic enzyme activity and inhibition studies demonstrated that AVR-Pii proteins specifically inhibit in vitro NADP-ME activity. Overall, we demonstrate that rice blast fungus, M. oryzae attenuates the host ROS burst via AVR-Pii-mediated inhibition of Os-NADP-ME2, which is indispensable in ROS metabolism for the innate immunity of rice. This characterization of the regulation of the host oxidative burst will help to elucidate how the products of AVR genes function associated with virulence of the pathogen.

• The Korean Journal of Physiology and Pharmacology
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• 제3권3호
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• pp.263-273
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• 1999

The role of phospholipase $A_2\;(PLA_2)$ in acute lung leak induced by intestinal ischemia was investigated in association with neutrophilic respiratory burst. To induce lung leak, we generated intestinal ischemia for 60 min prior to the 120 min reperfusion by clamping superior mesenteric artery in Sprague-Dawley rats. Acute lung leak was confirmed by the increased lung leak index and protein content in bronchoalveolar fluid. These changes were inhibited by mepacrine, the non-specific $PLA_2$ inhibitor. The lung myeloperoxidase (MPO) activity denoting the pulmonary recruitment of neutrophils was increased by intestinal I/R, but decreased by mepacrine. Simultaneously, the number of leukocytes in bronchoalveolar fluid was increased by intestinal ischemia/reperfusion (I/R) and decreased by mepacrine. Gamma glutamyl transferase activity, an index of oxidative stress in the lung, was increased after intestinal I/R but decreased by mepacrine, which implicates that $PLA_2$ increases oxidative stress caused by intestinal I/R. The $PLA_2$ activity was increased after intestinal I/R not only in the intestine but also in the lung. These changes were diminished by mepacrine. In the cytochemical electron microscopy to detect hydrogen peroxide, intestinal I/R increased the generation of the hydrogen peroxide in the lung as well as in the intestine. Expression of interleukin-1 (IL-1) in the lung was investigated through RT-PCR. The expression of IL-1 after intestinal I/R was enhanced, and again, the inhibition of $PLA_2$ suppressed the expression of IL-1 in the lung. Taken together, intestinal I/R seems to induce acute lung leak through the activation of $PLA_2$, the increase of IL-1 expression associated with increased oxidative stress by neutrophilic respiratory burst.

• The Korean Journal of Physiology and Pharmacology
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• 제2권4호
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• pp.479-491
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• 1998

In order to know the pathogenesis of adult respiratory distress syndrome (ARDS) in association with the oxidative stress by neutrophils, the role of platelet activating factor (1-0-alkyl-2-acetyl-snglycero-3-phosphocholine, PAF) was investigated during acute lung injury induced by interleukin- $1{\alpha}$ (IL-1) in rats. An insufflation of IL-1 into the rat's trachea increased the acetyltransferase activity in the lung and the increase of PAF content was followed. As evidences of acute lung injury by neutrophilic respiratory burst, lung leak index, myeloperoxidase activity, numbers of neutrophils in the bronchoalveolar lavage fluid, neutrophilic adhesions to endothelial cells and NBT positive neutrophils were increased after IL-1 treatment. In addition, a direct instillation of PAF into the trachea caused acute lung leak and the experimental results showed a similar pattern in comparison with IL-1 induced acute lung injury. For the confirmation of oxidative stress during acute lung leak by IL-1 and PAF, a histochemical electron microscopy was performed. In IL-1 and PAF treated lungs of rats, the deposits of cerrous perhydroxide were found. To elucidate the role of PAF, an intravenous injection of PAF receptor antagonist, WEB 2086 was given immediately after IL-1 or PAF treatment. WEB 2086 decreased the production of hydrogen peroxide and the acute lung leak. In ultrastructural study, WEB 2086 mitigated the pathological changes induced by IL-1 or PAF. The nuclear factor kappa B (NFkB) was activated by PAF and this activation was inhibited by WEB 2086 almost completely. Based on these experimental results, it is suggested that the PAF produced in response to IL-1 through the remodeling pathway has the major role for acute lung injury by neutrophilic respiratory burst. In an additional experiment, we can also come to conclude that the activation of the NFkB by PAF is thought to be the fundamental mechanism to initiate the oxidative stress by neutrophils causing release of proinflammatory cytokines and activation of phospholipase $A_2$.

• Tuberculosis and Respiratory Diseases
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• 제48권2호
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• pp.246-259
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• 2000

연구배경: 패혈증에 의해 발병하는 ARDS의 기전은 아직까지 명확히 알려져 있지 않다. 특히 패혈증시 폐 혈관내피세포 및 제 1, 2형 폐포세포의 손상이 호중구의 respiratory burst에 따른 oxidative stress에 의한 것인지는 아직도 논란의 대상이다. 또한 이때 oxidative stress의 직접적인 원인인 산소기 생성기전도 명확하지가 않다. 본 연구에서는 패혈증에 의한 ARDS 발병기전을 $PLA_2$의 작용과 호중구의 산소기 생성을 연관시켜 알아보고자 하였다. 방 법: Sprague-Dawley종 흰쥐에서 diethylmaleate(DEM)를 이용하여 glutathione을 고갈시킨 뒤 내독소를 기도 내로 분무하여 급성 폐손상을 유발하였다. 이때 oxidative stress를 평가할 수 있는 방법들, 즉 단백누출지수, 폐세척액 내 단백함량, 폐장 내 myelo-peroxidase(MPO)의 활동도 malondialdehyde(MDA)의 측정 및 GGT의 활성도를 측정하고 동시에 oxidative stress에 관여하는 $PLA_2$의 역할을 확인하기 위하여 비특이적 $PLA_2$ 억제제인 mepacrine(50mg/kg)을 복강 내 투여한 후 폐장 내 $PLA_2$의 활성도를 측정하였다. 또한 미세구조적 변화 및 세포화학적인 방법을 통해 조직 내 산소기의 생성을 확인, 비교하여 산소기 형성에 관여하는 $PLA_2$의 역할을 규명하였다. 결 과: Diethylmaleate에 의해 폐장 내 glutathione을 고갈시킨 뒤 내독소를 투여한 흰쥐에서, 내독소는 폐장 내 현저한 조직의 손상을 유발하였고, 동시에 oxidative stress의 증가를 관찰하였다. 즉 lipid peroxidation의 증가 및 GGT 활성도의 증가를 관찰하였다. 이러한 변화들은 폐장 내 호중구 침윤의 증가 및 $PLA_2$ 활성도와 관계가 있음을 확인하였고, 미세구조적 및 세포화학적인 방법으로 조직 내의 산소기 형성의 증가도 관찰하였다. 이러한 변화들이 비특이적 $PLA_2$ 억제제인 mepacrine의 작용에 의해 감소하는 것으로 미루어 보아 $PLA_2$가 내독소에 의한 oxidative stress에 관여한다고 생각되었다. 결 론: 내독소에 의해 유발되는 급성 폐손상에서 조직손상의 원인은 호중구의 respiratory burst에 따른 oxidative stress임을 확인하였고 이때 oxidative stress에 $PLA_2$의 활성화에 따라 생성되는 지질분자가 그 원인으로 사료되었다.

• 한국임상수의학회지
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• 제25권6호
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• pp.440-446
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• 2008

Glucocorticoids (GCs) are the most widely used immunosuppressive agents, but animals treated with GCs may experience deleterious side effects which limit their use in many clinical conditions. In the present study, we examined whether methylprednisolone sodium succinate (MPSS), a glucocorticoid, modulates circulating leukocyte numbers, phagocytic capacity and oxidative burst activity (OBA) of canine peripheral blood phagocytes, and whether tumor necrosis factor-alpha (TNF-$\alpha$) release is affected by MPSS injection. Neutrophilia and monocytosis were induced by the administration of a high dose of MPSS, which is the recommended protocol for canine patients with acute spinal cord injury. The injection of MPSS decreased the phagocytic capacity of canine PMNs but not PBMCs, and recovered 12 hours (hr) after the completion of MPSS dosing. The OBA of both PMNs and PBMCs was suppressed by MPSS, and restored 24 hr after the completion of dosing. The lipopolysaccharide-induced TNF-α release by PBMCs but not PMNs exposed to MPSS was reduced 12 hr after the completion of dosing, and recovered 48 hr after the completion of dosing. These results suggest that the application of MPSS protocol inhibits the innate immune functions of canine peripheral blood phagocytes for short time relatively.