• Tuberculosis and Respiratory Diseases
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• 제39권1호
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• pp.42-54
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• 1992

연구배경 : 내독소 투여시 혈장과 폐의 림프내에 cyclooxygenase 대사물과 lipoxygenase 대사물이 모두 증가하고, cyclooxygenase 차단제로 초기의 혈역학적 변화가 완화되어 내독소에 의한 급성 폐손상의 기전에서 cyclooxygenase 대사물의 역할이 중요시 되고 있다. 그러나 cyclooxygenase 억제약물이 내독소 투여시 후기에 관찰되는 폐혈관 투과성 증가에 미치는 효과에 대해서는 논란이 있는 실정이고 cyclooxygenase 대사과정에 관여하는 peroxidase에 의해서 산소기가 생성된다고 알려져 있어 cyclooxygenase 대사물이 직접 폐손상을 일으키는지 또는 대사과정에서 생성되는 산소기를 통해 간접적으로 관여 하는지는 확실히 규명되어 있지 않은 상태이다. 저자들은 cyclooxygenase 대사물이 내독소에 의한 급성 폐손상의 기전에 직접적 또는 간접적으로 관여하는지를 알아보기 위해 본 연구를 시행하였다. 방법 : 총 8마리의 집돼지를 내독소 투여군(n=3)과 indomethacin 전처치 후 내독소를 투여한 군(n=5)으로 나누어 시간 경과에 따른 혈력학적 지표의 변화, 혈장내 산화 glutathione(GSSG) 및 기관지폐포세척액내의 알부민 농도를 측정하여 indomethacin 전처치가 내독소에 의한 급성 폐손상에 미치는 영향을 관찰하였다. 결과 : 1) 내독소 투여 후 phase 1(0-2 hr)과 phase 2(2-4.5 hr)에 걸쳐서 심박출양은 감소되고 평균 폐동맥압, 폐혈관저항, 폐포동맥간산소분압차는 증가되었으며 indomethacin 전처치로 두 phase의 변화가 모두 완화되었다. 2) phase 2에서 내독소에 의해 GSSG가 기저치에 비해 유의하게 증가했는데 indomethacin 전처치로는 완화되지 않았다. 3) 기관지폐포세척액내 알부민농도와 투과성지표는 내독소 투여군에 비해 indomethacin 전처치군에서 유의하게 낮았다. 결론 : 이상의 결과로 내독소에 의한 돼지의 급성 폐손상에는 cyclooxygenase 대사물이 초기와 후기 모두에 관여할 것으로 생각되고 indomethacin이 산소기에 의한 산화반응에 영향을 미치지 않는 것으로 보아 산소기를 통한 간접작용보다는 cyclooxygenase 대사물이 직접 병인론적 기전에 관여할 것으로 사료된다.

• The Korean Journal of Physiology and Pharmacology
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• 제2권2호
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• pp.241-249
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• 1998

Platelet-activating factor(PAF) enhanced interleukin-1(IL-1) activity by the interaction with a specific receptor in rat alveolar macrophages. In this study, we investigated the role of endogenous arachidonate metabolites and intracellular calcium mobilization in the PAF-induced IL-1 activity. Alveolar macrophages were preincubated with 5-lipoxygenase and cyclooxygenase inhibitors 30 min before the addition of PAF and lipopolysaccharide(LPS). After 24h culture, IL-1 activity was measured in the supernate of sample using the thymocyte proliferation assay. Inhibition of 5-lipoxygenase by nordihydroguaiaretic acid and AA-861 completely blocked the PAF-induced enhancement of IL-1 activity with $IC_{50}\;of\;2\;{\mu}M\;and\;5\;{\mu}M$, respectively. In contrast, the inhibition of cyclooxygenase pathway by indomethacin and ibuprofen resulted in the potentiation in PAF-induced IL-1 activity with maximal effect at $1\;{\mu}M\;and\;5\;{\mu}M$, respectively. In addition, leukotriene $B_4$ and prostaglandin $E_2$ production were observed in PAF-stimulated alveolar macrophage culture. As could be expected, 5-lipoxygenase and cyclooxygenase inhibitors abolished PAF- stimulated leukotriene $B_4$ and prostaglandin $E_2$ production, respectively. The effects of PAF on intracellular calcium mobilization in alveolar macrophages were evaluated using the calcium-sensitive dye fura-2 at the single cell level. PAF at any dose between $10^{-16}\;and\;10^{-8}$ M did not increase intracellular calcium. Furthermore, there was no effective change of intracellular calcium level when PAF was added to alveolar macrophages in the presence of LPS or LPS+LTB4, and 4, 24 and 48h after treatment of these stimulants. Together, the results indicate that IL-1 activity induced by PAF is differently regulated through subsequent induction of endogenous 5-lipoxygenase and cyclooxygenase pathways, but not dependent on calcium signalling pathway.

• 한국식품위생안전성학회지
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• 제8권3호
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• pp.157-161
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• 1993

본 연구는 ethanol의 reactive metabolite인 acetaldehyde의 일차 배양혈관 평활근 세포에 대한 독성 발현 양식을 규명하기 위한 연구의 일환으로, prostaglandin 합성과 세포독성과의 관련성 여부를 확인하기 위하여 수행되었다. Acetaldehyde는, 일차 배양 혈관 평활근 세포에서의 prostaglandin 합성을 현저히 증가 시켰으며, 이때, cyclooxygenase activity 는 큰 변화없거나 오히려 감소시키는 경향을 보였다. Cyclooxygenase inhibitor 인 indometancin은 acetaldehyde에 의한 LDH release를 현저히 차단시켰으며, aspirin 및 salicylic acid는 전혀 영향을 주지 못했다. Phospholipase $A_2\;(PLA_2)$ inhibitor로 알려져 있는 dexamethasone은 유의적인 세포 독성 경감 작용을 보이지 못하였으며, Lipoxygenase inhibitor 들인 NDGA, propyl gallate 등은 현저한 독성 경감 효과를 보였다. 이상의 결과로부터 acetaldehyde에 의한 일차 배양 혈과 평활근 세포에서의 prostaglandin 합성 증가는 Cell death에 대한 직접적인 원인이 아님을 추론할 수 있었으며, $PLA_2/lipoxygenase$ inhibitor들의 강력한 세포독성 경감 작용으로 미루어 볼 때, acetaldehyde 에 의한 세포독성은 lipoxygenase 대사 산물 혹은 $PLA_2$의 직접 작용에 기인할 가능성을 확인할 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제4권6호
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• pp.525-530
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• 2000

During reperfusion of skeletal muscle after ischemia, lipid mediators, mainly eicosanoids, are released and may have a role in the pathogenesis of reperfusion injury. To validate the role of eicosanoids in the ischemia-reperfusion induced functional deficits in skeletal muscle, we compared muscle edema and the changes of eicosanoid concentration in the rat hind limb after ischemia-reperfusion injury by application of tourniquet. After 4 hours of ischemia, reperfusion was established for 4 hours by releasing tourniquet. To assess tissue damage, edema, and wet/dry weight ratios were determined and the eicosanoid concnentrations were measured by the HPLC. The muscle edema and the release of cyclooxygenase metabolites were not induced by the ischemia itself rather they were significantly increased by reperfusion. Indomethacin treatment ameliorated limb edema and decreased the release of $6-keto-PGF_{1{\alpha}},$ thromboxane $B_2,$ and $PGE_2$ inducedby reperfusion. But the inhibitory effect of indomethacin on edema (35%) was relatively low than the inhibitory effect on release of cyclooxygenase metabolites (up to 69%) by reperfusion. These results support the view that cyclooxygenase products may play a significant role in the formation of muscle injury by ischemia-reperfusion and suggest that nonsteroidal antiinflammatory agents might be partially beneficial to the management of acute limb ischemia-reperfusion injury.

• The Korean Journal of Physiology and Pharmacology
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• 제2권6호
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• pp.779-786
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• 1998

A reversed-phase high-performance liquid chromatogrphy (RP-HPLC) has been developed to analyze the metabolites of arachidonic acid based on the specificities of ultraviolet absorption of these various metabolites and is sensitive to the nanogram level. This procedure makes it possible to extract complex mixtures of eicosanoids efficiently with a single step and to analyze them simultaneously by RP-HPLC from biological samples using octadesylsilyl silica extraction column and $PGB_2$ as an internal standard. The cyclooxygenase products {prostaglandin $(PG)D_2,\;PGE_1,\;PGE_2,\;PGF_{1{\alpha}},\;PGF{2{\alpha}},\;6-keto-PGF_{1{\alpha}},$ and thromboxane $B_2(TXB_2)}$ and lipid peroxidation product, isoprostanes, of arachidonic acid were monitored by one isocratic HPLC system at 195 nm wavelength. The lipoxygenase products ${leukotriene(LT)B_4,\;LTC_4,\;LTD_4,$ and 5-hydroxyeicosatetraenoic acid (5-HETE), 12-HETE, 15-HETE} were measured by another isocratic HPLC system at 280 nm for LTs and 235 nm for HETEs. This method provides a simple and reliable way to extract and assess quantitatively the final arachidonic acid metabolites.

• Preventive Nutrition and Food Science
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• 제11권1호
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• pp.1-5
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• 2006

Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of linoleic acid that have been used to reduce the incidence, growth and metastasis of breast, colon, prostate and gastric cancer in animals. CLA could reduce tumor growth by altering angiogenesis; a process requiring associated angiogenic factors such as vascular endothelial growth factor (VEGF). In this study, we determined whether CLA could modulate the expression of VEGF in murine mammary tumor cells and adipocytes. The c9, t11-CLA isomer reduced VEGF transcripts and protein when mammary tumor cells were stimulated with PMA. That isomer also reduced VEGF expression in un stimulated mouse 3T3-L1 adipocytes. Since VEGF can be regulated by cyclooxygenase-2 (COX-2), we determined whether CLA could alter COX-2 enzyme expression and $PGE_2$ production. The c9, t11-CLA isomer reduced not only COX-2 enzyme expression but also $PGE_2$ production. Thus, c9, t11-CLA could modulate neovascularization by alteration of VEGF expression from mammary tumor cells and adipocytes by reducing COX-2 metabolites.

• Fisheries and Aquatic Sciences
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• 제6권3호
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• pp.130-134
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• 2003

Proinflammatory effects of bacterial lipopolysaccharide (LPS) have been assessed by analysing the induction of two inflammatory genes, $interleukin-1\beta$ $(IL-1\beta)$ and cyclooxygenase-2 (COX-2), in rainbow trout (Oncorhynchus mykiss) macrophage cells. Production of a metabolite of arachidonic acid by COX-2, prostaglandin $E_2\;(PGE_2)$, was also analysed in macrophage cells after LPS stimulation. Northern blot analysis revealed that LPS $(5{\mu}g/mL)$ significantly upregulated $IL-1\beta$ (54 times) and COX-2 (40.7 times) gene expression in macrophage cells after 4 h stimulation. According to RT-PCR (Reverse Transcription Polymerase Chain Reaction) analysis, $IL-1\beta$ gene induction in LPS stimulated macrophage cells was started within 1h and significantly increased thereafter until 4h. Meanwhile, COX-2 gene induction by LPS was delayed in comparison with $IL-1\beta$ gene induction as a faint band was observed after 4h stimulation in head kidney macrophage cells. LPS also significantly increased $PGE_2$ production in head kidney leucocytes, presumably via activating COX-2 expression that metabolites arachidonic acid to $PGE_2$. In conclusion, it was demonstrated that LPS could induce two main inflammatory and immune related genes, $IL-1\beta$ and COX-2, and increase $PGE_2$ production in trout head kidney macrophage cells, representing a strong inflammatory activity.

• 동의생리병리학회지
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• 제20권4호
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• pp.1027-1031
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• 2006

In oriental medicine, Geijibokryunghwan(GBH) was used to improvement various symptoms created by the thrombosis. We investigated the effects of an oriental medicinal prescriptions, Geijibokryunghwan (GBH) consisting of herbs of Cinnamomi Ramufus (Geiji; 桂枝), Poria cocos (Bokrung; 茯?), Moutan Cortex Radicis(Modanpi; 牧丹皮), Paeoniae Radix (Jakyak; 芍藥) and Persicae Semen (Doin; 桃仁) on tumor growth-inhibitory activity and cancer chempreventive activity in assays representing three maior stages of carcinogenesis. Cancer chempreventive agents include nonsteroidal anti-inflammatory drugs (NSAIDS) such as indomethacin, aspirin, piroxicam, and sulindac, all of which inhibit cyclooxygenase (COX). Effects of the GBH extracts on carrageenan-induced edema Inflammation using female (C57BL/6XC3H) Fl (B6C3Fl ) mice and tumorigenesis were examined. Finally, cyclooxygenase metabolites were determined after extracts treatment. These data suggest that GBH extracts merits investigation as a potential cancer chempreventive agent in humans.

• Nutrition Research and Practice
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• 제2권2호
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• pp.55-61
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• 2008

We investigated the combinatorial effects of different doses of dietary soy isoflavones (SI) and fructooligosaccharide (FOS) in a rat model of colon cancer. We hypothesized that increased bioavailability of SI metabolites due to dietary FOS may increase production of bioactive equol and affect colon carcinogenesis in a dose-dependent manner. Sprague-Dawley male rats were injected with 12-dimethylhydrazine (DMH) and were providec experimental diets that contained 0, 10, 50, 150, or 500 mg SI per kg of diet and 6% FOS for 12 weeks. The number of aberrant crypt foci (ACF) and the expression of cyclooxygenase-2 (COX-2) in colonic tissues were significantly decreased in the 6% FOS-fed groups compared to the control group. Gut transit time and fecal pH were significantly lower, and fecal concentrations of bifidobacteria were increased with 6% FOS. However, dietary SI supplementation in combination with 6% dietary FOS did not affect ACF formation or COX-2 expression. Plasma equol concentrations were dose-dependently increased by supplementation of SI up to 500 mg/kg of diet. In conclusion, SI supplementation up to 500 mg/kg of diet appeared to have no additive beneficial effects in rats with chemically-induced colon cancer that were fed 6% FOS, although plasma equol was dose-dependently increased.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.3048-3054
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• 2012

The use of aspirin is widely recommended for the prevention of heart attacks owing to its ability to inhibit platelet activation by irreversibly blocking cyclooxygenase 1. However, aspirin also affects the fibrinolytic and hemostatic pathways by mechanisms that are not well understood, causing severe hemorrhagic complications. Here, we investigated the ability of aspirin and aspirin metabolites to inhibit thrombin-activatable fibrinolysis inhibitor (TAFI), the major inhibitor of plasma fibrinolysis. TAFI is activated via proteolytic cleavage by the thrombin-thrombomodulin complex to TAFIa, a carboxypeptidase B-like enzyme. TAFIa modulates fibrinolysis by removing the C-terminal arginine and lysine residues from partially degraded fibrin, which in turn inhibits the binding of plasminogen to fibrin clots. Aspirin and its major metabolites, salicylic acid, gentisic acid, and salicyluric acid, inhibit TAFIa carboxypeptidase activity. Salicyluric acid effectively blocks activation of TAFI by thrombin-thrombomodulin; however, salicylates do not inhibit carboxypeptidase N or pancreatic carboxypeptidase B. Aspirin and other salicylates accelerated the dissolution of fibrin clots and reduced thrombus formation in an in vitro model of fibrinolysis. Inhibition of TAFI represents a novel hemostatic mechanism that contributes to aspirin's therapy-associated antithrombotic activity and hemorrhagic complications.