• The korean journal of orthodontics
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• v.33 no.3 s.98
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• pp.199-210
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• 2003

Tooth movement is the result of bone metabolism in the periodontium, where various cytokines take important roles. Interleukin-6(II-6) and nitrous oxide (NO) were reported to be secreted from osteoblasts in the process of bone resorption. The mechanism of the process has not been clearly understood, but the activation of mitogen-activated protein kinase (MAPK) was known to be an important process in the release of the inflammatory cytotines in macrophages. In this regard, to prove the role of MAPK in the release of IL-6 and NO in MC3T3E-1 osteoblasts, Northern blot analysis, Western blot analysis and immune complex kinase assay were used. As a result, the treatment of MC3T3E-1 osteoblast cultures with combined $interferon-\gamma(IFN-\gamma)$, lipopolysaccharide (LPS) and tumor necrosis $factor-\alpha(TNF-\alpha)$ induces expressions of inducible nitric oxide synthase (iNOS) and IL-6, resulting in sustained releases of large amounts of NO and IL-6. However, $IFN-\gamma,\;LPS,\;and\;TNF-\alpha$ individually induce a non-detectable or small amount of NO and IL-6 in MC3T3E-1 osteoblasts. The role of MAPK activation in the early intracellular signal transduction involved in iNOS and IL-6 transcription in the combined agents-stimulated osteoblasts has been investigated. The p38 MAPK pathway is specifically involved in the combined agents-induced NO and IL-6 release, since NO and IL-6 release in the presence of a specific inhibitor of p38 MAPK, 4-(4-fluorophenyl)-2-(4-metylsulfinylphenyl)-5-(4-metylsulfinylphenyl)-5-(4-pyridyl)imidazole) (SB203580), were significantly diminished. In contrast, PD98059, a specific inhibitor of MEK1, had no effect on NO and IL-6 release. Northern blot analysis showed that the p3a MAPK pathway controlled the iNOS and IL-6 transcription level. These data suggest that p38 MAPK play an important role in the secretion of NO and IL-6 in $LPS/IFN{\gamma}-or\;TNF-\gamma-treated\;MC3T3E-1$ osteoblasts.

• Proceedings of the Ginseng society Conference
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• 1984.09a
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• pp.83-88
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• 1984

It is now well established that the rodenticide Vacor (N-3-pyridyl-mehtyl-N'-p-nitropheny-lurea) causes a hyperglycemia in human and rats. It is also reported that there are some components (DPG-3) in ginseng radix which cause hypoglycemic effect on alloxan diabetic mice. In the present study, attempts were made to demonstrate in Vacor-poisoned rats the hypo-glycemic activity of red ginseng component(RGC), which was extracted by Kimura's DPG-3 extraction procedure and found to be effective for lowering a hyperglycemia in alloxan-diabetic rats. Vacor in a dose of $LD_{50}$ (10mg/kg) produced a glucose intolerance with a paradoxical moderate increase in blood immunoreactive insulin and derangement in glucose metabolism of epididymal adipocytes in rats. Although RGC (20mg/kg, i.p.) did not exert any significant influence on a hyperglycemia induced by large lethal doses (25mg/kg) of Vacor ingestion, it improved the LDso Vacor-induced glucose intolerance and caused a further increase in blood insulin levels in Vacor-poisoned rats. The administration of RGC (20mg/kg, i.p.) normalized Vacor-induced depression of glucose metabolism and lipogenesis in the epididymal adipocytes with an improvement of reduced responses to insulin of adipocytes from Vacor-poisoned rats. These results suggest that some red ginsneng components contained in RGC fraction normalize the depressed peripheral glucose unitlization and insulin response and eventually lead to an improvement of abnormal glucose tolerance developed in rats poisoned with small doses of Vacor.