• 제목/요약/키워드: reoxygenation

검색결과 65건 처리시간 0.035초

Hypoxia/Reoxygenation과 Acidosis가 위선세포에서 위산분비와 NO Synthase 활성에 미치는 영향 (Acid Secretion and Nitric Oxide Synthase Activity in Gastric Glands Following Hypoxia/Reoxygenation and Acidosis)

  • 김혜영;김경환
    • 대한약리학회지
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    • 제31권1호
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    • pp.75-84
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    • 1995
  • NO의 위산분비에 대한 작용을 규명하기 위하여 분리한 토끼위선세포에서 hypoxia/reoxygenation과 acidosis후 위산분비와 NO synthase 활성을 측정하였다. 분리한 위선세포에 30분의 hypoxia와 1시간의 reoxygenation을 주었으며, acidosis를 위하여 배지의 pH를 6.0과 4.0으로 변화시켜 실험하였다. 위산분비는 위선세포 내와 외의 $[^{14}C]-aminopyrine$ 축적비율로 측정하였으며, NO synthase 활성은 NO의 전구물질인 $[^{14}C]L-arginine$으로부터 $[^{14}C]-citrulline$으로의 전환율로 결정하였다. 결과로서 dibutyryl cAMP는 농도 의존적으로 위산분비를 촉진시켰으나 NO synthase 활성엔 영향을 주지 않았다. Hypoxia/reoxygenation은 기초 및 자극 위산분비를 억제하였으며 acidosis에 의해 위산분비억제는 더욱 심화되었다. Constitutive NO synthase 활성 역시 hypoxia/reoxygenation과 acidosis에 의해 억제되었다. 결론적으로 hypoxia/reoxygenation과 acidosis 같은 위점막의 병적상태는 위산분비와 NO 유리를 모두 억제하나, 기초상태의 위선에서 dibutyryl cAMP에 의한 위산분비 촉진에 대한 NO의 직접적인 작용은 확인되지 않았다.

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성향정기산가보공영(星香正氣散加補公英)과 단미(單味)들이 Hypoxia-reoxygenation에 의해 손상받은 Mouse Neuroblastoma 2a Cells에 미치는 영향(影響) (The effects Sunghyangjungkisan-ga-pogongng and herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation)

  • 유진석;김종우;강철훈;황의완
    • 동의신경정신과학회지
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    • 제16권1호
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    • pp.19-41
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    • 2005
  • Object : This study was designed to asses the effect of Sunghyangjungkisan-ga-pogongng and herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation. Method : Mouse neuroblastoma 2a (N2a) cells were measured by MTT assay and LDH assay after 48h hypoxia and 6h reoxygenation, Mouse neuroblastoma 2a (N2a) cells were treated by SHJG+P and herbs. Result : 1. SHJG+P was effective on LDH assay of hypoxia and reoxygenation. 2. The herbs were generally effective on LDH assay of hypoxia and reoxygenation. In MTT assay of hypoxia JP and GC were effecctive. In LDH assay of hypoxia all of herbs were effective. DMH, BC, SY, NS were more effective than other herbs. In LDH assay of reoxygenation KH, BH, BBR, DMH were especially effective. In MTT assay of reoxygenation most of herbs were not effective. But GC, SY, BH, JP were effective. Conclusion : The results imply that SHJG+P and all of berbs may have protective effect on dementia and GC, SY, BH, JP may have protective effect.

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흰쥐 관류간 모델에서 저산소 및 산소재도입시 vitamin C가 간장기능에 미치는 영향 (The Effect of Vitamin C on Hypoxia/reoxygenation Induced Hepatic Injury in Isolated Perfused Rat Liver)

  • 고준일;조태순;이선미
    • Biomolecules & Therapeutics
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    • 제5권1호
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    • pp.1-7
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    • 1997
  • This study was done to investigate the effect of vitamin C on hypoxia/reoxygenation-induced hepatic injury ul isolated perfused rat liver. Isolated livers from rats fasted 18 hours were subjected to 45 min of hypoxia followed by reoxygenation for 45 min. The perfusion medium used was Krebs-Henseleit bicarbonate buffer (pH 7.4) and 0.5 mmol/L of vitamin C was added to the perfusate. Alanine aminotransferase (ALI) and lactate dehydrogenase (LDH) levels were significantly increased by hypoxia/reoxygenation. These increases were augmented by vitamin C. Glucose output and bile flow were markedly decreased by hypoxia/reoxygenation. Vitamin C aggavated the decrease of glucose output but had little effect on bile flow. Our findings suggest that hypoxia/reoxygenation diminishes hepatic metabolic and secretory functions, and vitamin C significantly aggravates these changes.

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건뇌양(健腦揚)과 단미(單味)들이 Hypoxia-Reoxygenation에 의해 손상받은 Mouse Neuroblastoma 2a Cells에 미치는 영향(影響) (The Effects Kunnuetang and Herbs on Mouse Neuroblastoma 2a Cells Damaged by Hypoxia-reoxygenation)

  • 염창섭;김종우;강철훈;황의완
    • 동의신경정신과학회지
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    • 제16권2호
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    • pp.73-88
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    • 2005
  • Object : This study was designed to asses the effect of Kunnuetang and herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation. Method : Mouse neuroblastoma 2a (N2a) cells were measured by MTT assay and LDH assay after 48h hypoxia and 6h reoxygenation. Mouse neuroblastoma 2a (N2a) cells were treated by Kunnuetang, Duchang and Daejo. Result : 1. Kunnuetang, was effective on LDH assay of hypoxia and reoxygenation. 2. Duchang and Daejo were generally effective on LDH assay of hypoxia and reoxygenation. 3. In MTT assay of hypoxia Kunnuetang was not effective. Duchung and Daejo were not generally effective on MTT assay, but in certain condition Herbs were effective. 4. In MTT assay of reoxygenation Kunnuetang and Daejo were not effective. But Duchung was effective in certain condition. Conclusion : The results suggest that Kunnuetang, Duchang and Daejo may have protective effect on vascular dementia and ad patient.

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Changes in drug metabolism during hypoxia/reoxygenation in isolated perfused rat

  • Seo, Min-Young;Cho, Tai-Soon;Lee, Sun-Mee
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1997년도 춘계학술대회
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    • pp.98-98
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    • 1997
  • This study was done to investigate the effect of vitamin E on hypoxia/reoxygenation-induced hepatic injury in isolated perfused rat liver. Rats were pretreated with vitamin E or vehicle(soybean oil). Isolated livers from fasted 18 hours were subjected to 45min of low flow hypoxia or N$_2$ hypoxia followed by reoxygenation for 30min. The perfusion medium used was KHBB(pH 7.4) and 50${\mu}$㏖/$\ell$ of ethoxycoumarin was added to the perfusate to determine the ability of hepatic drug-metabolizing systems, In low flow hypoxia model, total glutathione and oxidised glutathione levels were significantly increased by hepoxia/reoxygenation with slight increase in LDH levels. These increases were prevented by vitamin E pretreatment. In N$_2$ hypoxia model, LDH, total glutathione and oxidized glutathione levels were increased significantly by hypoxia but restored to normal level by reoxygenation. Vitamin E had little effect on this hypoxic damage. There were no significant changes in the rate of hepatic oxidation of 7-EC to 7-HC in both hepoxic models. But, the subsequent conjugation of 7-HC by sulfate or glucuronic acid were significantly decreased by hypoxia, but restored by reoxygenation in both hypoxia models. As opposed to our expectation, treatment with vitamin E aggrevated the decrease of the rate of conjugation and even inhibited the restoration by reoxygenation. Our findings suggest that hypoxia/reoxygenation diminishes phase II drug metabolizing function and this is, in part, related to decreased energy level.

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황연해독탕(黃連解毒湯)이 Hypoxia-reoxygenation에 의해 손상 받은 Mouse Neuroblastoma 2a Cells에 미치는 영향(影響) (The effects of Hwangryunhaedoktang and herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation)

  • 안상훈;김종우;강철훈;황의완
    • 동의신경정신과학회지
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    • 제17권2호
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    • pp.37-59
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    • 2006
  • Objective : This study was designed to asses the effect of Hwangryunhaedoktang and herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation. Method : Mouse neuroblastoma 2a (N2a) cells were measured by MTT assay and LDH assay after 48h hypoxia and 6h reoxygenation. Mouse neuroblastoma 2a (N2a) cells were treated by Hwangryunhaedoktang and herbs. Result : 1. Hwangryunhaedoktang was effective on LDH assay of hypoxia and reoxygenation. 2. All of herbs were generally effective on LDH assay of hypoxia and reoxygenation. In LDH assay of hypoxia, the effects of herbs depended on concentration. In MTT assay of hypoxia, Coptidis Rhizoma and Gardeniae Fructus were effective. In MTT assay of reoxygenation most of herbs were not effective. But Phellodendri Cortex was effective in high concentration. Conclusion : The results imply that Hwangryunhaedoktang and all herbs of it nay have protective effect on dementia and aging.

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Reoxygenation Stimulates EDRE(s) Release from Endothelial Cells of Rabbit Aorta

  • Suh, Suk-Hyo;Han, Jae-Jin;Park, Sung-Jin;Choi, Jai-Young;Sim, Jae-Hoon;Kim, Young-Chul;Kim, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
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    • 제3권4호
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    • pp.393-404
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    • 1999
  • We have reported that hypoxia stimulates EDRF(s) release from endothelial cells and the release may be augmented by previous hypoxia. As a mechanism, it was hypothesized that reoxygenation can stimulate EDRF(s) release from endothelial cells and we tested the hypothesis via bioassay experiment. In the bioassay experiment, rabbit aorta with endothelium was used as EDRF donor vessel and rabbit carotid artery without endothelium as a bioassay test ring. The test ring was contracted by prostaglandin $F_{2a}\;(3{\times}10^{-6}\;M)$ which was added to the solution perfusing through the aorta. Hypoxia was evoked by switching the solution aerated with 95% $O_2/5%\;CO_2$ mixed gas to one aerated with 95% $O_2/5%\;CO_2$ mixed gas. Hypoxia/reoxygenation were interexchanged at intervals of 2 minutes (intermittent hypoxia). In some experiments, endothelial cells were exposed to 10-minute hypoxia (continuous hypoxia) and then exposed to reoxygenation and intermittent hypoxia. In other experiments, the duration of reoxygenation was extended from 2 minutes to 5 minutes. When the donor aorta was exposed to intermittent hypoxia, hypoxia stimulated EDRF(s) release from endothelial cells and the hypoxia-induced EDRF(s) release was augmented by previous hypoxia/reoxygenation. When the donor aorta was exposed to continuous hypoxia, there was no increase of hypoxia-induced EDRF(s) release during hypoxia. But, after the donor aorta was exposed to reoxygenation, hypoxia-induced EDRF(s) release was markedly increased. When the donor aorta was pretreated with nitro-L-arginine $(10^{-5}$ M for 30 minutes), the initial hypoxia-induced EDRF(s) release was almost completely abolished, but the mechanism for EDRF(s) release by the reoxygenation and subsequent hypoxia still remained to be clarified. TEA also blocked incompletely hypoxia-induced and hypoxia/reoxygenation-induced EDRF(s) release. EDRF(s) release by repetitive hypoxia and reoxygenation was completely blocked by the combined treatment with nitro-L-arginine and TEA. Cytochrome P450 blocker, SKF-525A, inhibited the EDRF(s) release reversibly and endothelin antgonists, BQ 123 and BQ 788, had no effect on the release of endothelium-derived vasoactive factors. Superoxide dismutase (SOD) and catalase inhibited the EDRF(s) release from endothelial cells. From these data, it could be concluded that reoxygenation stimulates EDRF(s) release and hypoxia/reoxygenation can release not only NO but also another EDRF from endothelial cells by the production of oxygen free radicals.

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Effect of Trolox C on Hypoxia/Reoxygenation-Induced Injury in Isolated Perfused Rat Liver

  • Lee, Sun-Mee;Cho, Tai-Soon
    • Archives of Pharmacal Research
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    • 제20권5호
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    • pp.471-475
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    • 1997
  • Livers isolated from 18 hours fasted rats were subjected to N$_{2}$ hypoxia (for 45 min) followed by reoxygenation (for 45 min). The perfusion medium used was Krebs-Henseleit bicarbonate buffer (KHBB, pH 7.4). Lactate and alanine were added as gluconeogenic and ureagenic substrates and Trolox C was also added to perfusate. Oxygen consumption, lactate dehydrogenase (LDH), alanine transaminase (ALT), total glutathione, oxidized glutathione, bile flow, glucose and urea were measured. After hypoxia oxygen consumption significantly dropped but Trolox C had no influence on this decrease. ALT and LDH were significantly increased by hypoxia/reoxygenation. This increase was markedly attenuated in the presence of Trolox C. The total glutathione and oxidized glutathione efflux increased following hypoxia, which were prevented by the treatment of Trolox C. Bile flow rate decreased following hypoxia/reoxygenation but did not continue to decrease in the reoxygenation phase by Trolox C. Following hypoxia/reoxygenation glucose and urea releases decreased. Trolox C had no influence on inhibition of glucose and urea production. These results suggest that Trolox C protected the liver cells against hypoxia/reoxygenation injury, yielding further evidence for a causative role of oxidative stress in this model.

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The Replicon Initiation Burst Released by Reoxygenation of Hypoxic T24 Cells is Accompanied by Changes of MCM2 and Cdc7

  • Martin, Leenus
    • BMB Reports
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    • 제40권5호
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    • pp.805-813
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    • 2007
  • Although MCM2 is obviously important for the initiation of eukaryotic DNA replication, its role in $O_2$ dependent regulation of replicon initiation is poorly understood. In this report, I analysed the changes of MCM2 during the transition from hypoxically suppressed replicon initiation to the burst of initiation triggered by reoxygenation in T24 cells. A high level of chromatin bound and nucleosolic MCM2 was found under the hypoxic replicon arrest. In contrast low cytosolic MCM2 was noticed. Recovery of $O_2$ induced phosphorylation and diminution of chromatin bound MCM2, whereas cytosolic MCM2 increased. The level of chromatin bound Cdc7 did not change significantly upon reoxygenation. However, after reoxygenation, significant phosphorylation of Cdc7 and an increase of coimmunoprecipitation with its substrate (MCM2) were observed. This provides a hint that reoxygenation may promote the kinase activity of Cdc7. These changes might be the critical factors in $O_2$ dependent regulation of replicon initiation. Moreover, phosphorylation of Cdc7 by Cdk2 can be observed in vitro, but seems to fail to regulate the level of chromatin bound Cdc7 as well as the changes of MCM2 in response to reoxygenation of hypoxically suppressed cells.

천왕보심단(天王補心丹)과 단미(單味)들이 Hypoxia-Reoxygenation에 의해 손상받은 Mouse Neuroblastoma 2a Cells에미치는 영향(影響) (The effects of Chenwangbosim-Dan and herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation)

  • 김상호;김종우;강철훈;황의완
    • 동의신경정신과학회지
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    • 제17권2호
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    • pp.15-36
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    • 2006
  • Objective : This study was designed to assess effect of and Chenwangbosim-Dan(CWBSD) herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation. Method : Mouse neuroblastoma 2a (N2a) cells were measured by MTT assay and LDH assay after 48h hypoxia and 6h reoxygenation. Mouse neuroblastoma 2a (N2a) cells were treated by CWBSD and herbs. Result : 1. In MTT assay of hypoxia CWBSD and BJI, SJH, IS, CHR, HS among all of herbs were effective. Especially CWBSD and IS were highly effective. 2. In MTT assay of reoxygenation SJI, SJH, VJ, IS, BJI were effective. Especially SJI, SJH, YJ were highly effective. 3. In LDH assay of hypoxia CWBSD, DS, DG, SJH, OMZ were effective. Especially CWBSD, DG were highly effective. 4. In LDH assay of reoxygenation all of herbs except CWBSD and BJI were generally effective. Especially CHR, SJH, YJ, OMZ, HS were highly effective. Conclusion : The results suggest that CWBSD, and it's ingradient(especially SJH, CHR and SJI) may have protective effect on condition of oxidative stress.

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