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문교철(Kyo Cheol Mun),곽춘식(Chun Sik Kwak) 대한소화기학회 1998 대한소화기학회지 Vol.30 No.1
N/A Background/Aims: Protective role of antioxidant enzymes under the cholestasis was evaluated. Methods:: The activity of xanthine oxidase, the amount of superoxide radical production, and the activities of antioxidant enzymes such as superoxide dismutase, catalase and glutathione peroxidase were measured under the cholestasis. Results: Xanthine oxidase activity, Vmax value of this enzyme and superoxide radical production were iri'creased after CBD ligation. Superoxide dismutase arid glutathione peroxidase activities showed no significant changes throughout the experiments. Catalase activity and Vmax value of this enzyme in the liver was signifi- cantly decreased after CBD ligation. Conclusions: Although the production of oxygen free radicals is increased due to increased xanthine oxidase, anti- oxidant enzymes do not play their protective role to oxygen free radicals due to decreased biosynthesis.
박학열(Hak Youle Park),문교철(Kyo Cheol Mun) 대한소화기학회 2002 대한소화기학회지 Vol.39 No.4
Backgroud/Aims: Oxygen free radicals can be defined as oxygen molecules or molecular fragments that have an unpaired electron. They are formed in all living organisms during physiological and pathophysiological metabolism, and cause cell and tissue damages due to their high chemical reactivity. They can react with macromolecules including lipid, protein and DNA. Peroxidation of lipids exposed to oxygen free radicals is responsible for the damages of cells and tissues in vivo, which may cause cancer, inflammatory disease and liver disease. During the regeneration of the liver, there might be some alterations for metabolism of oxygen free radicals, which causes damage to regenerating liver. To know the degree of damage by oxygen free radicals in cell organelles of regenerating liver, hepatectomy was performed to the Sprgue-Dawley rats. Methods: From the regenerating liver obtained at day 3 after hepatectomy homogenate, mitochondria, microsome, cytosol, nuclei and plasma membrane were obtained as samples by sucrose linear density gradient centrifuger. Then, their malondialdehyde levels were measured by thiobarbituric acid assay. Results: The level of malondialdehyde level were increased in the homogenate, mitochondria, microsome and cytosol of the regenerating liver than in those of the original liver. Conclusions: These results suggest that mitochondria and microsome are susceptible to the oxygen free radicals in the regenerating liver. (Korean J Gastroenterol 2002;39:284-288)
Cyclosporine 에 의한 용혈에서 Melatonin 의 효과
곽춘식(Chun Sik Kwak),문교철(Kyo Cheol Mun),서성일(Seong Il Suh) 대한신장학회 2001 Kidney Research and Clinical Practice Vol.20 No.5
N/A Hemolysis is one of the side effects of cyclosporine(CsA). Some experimental and clinical data have strongly suggested that CsA-induced hemolysis is resulted from the increased production of free radical species by CsA. Melatonin, a pineal secretory product, acts as a highly efficient free radical scavenger. Thus, melatonin may have a protective effect on the CsA-induced hemolysis. To test this hypothesis, the final concentration of 4.2×106/mL with human erythrocytes was incubated in test tube at 37℃ water bath with 1.67 mg/mL of CsA and 72 nmol/mL of melatonin. The degree of hemolysis and the amount of malondialdehyde which gives an indirect index of oxidative injury were measured in group 1 containing only isotonic buffer solution, in group 2 containing only CsA, and in group 3 containing both CsA and melatonin. The degrees of hemolysis in group 2 were higher than those of group 1. The degrees of hemolysis in group 3 were higher than those of group 1, and lower than those of group 2. The amounts of malondialdehyde in group 2 were higher than those of group 1. The amounts of malondialdehyde in group 3 were higher than those of group 1, and lower than those of group 2. These results indicate that the direct contact of erythrocytes with CsA results in free radical mediated hemolysis and the hemolysis by CsA can be prevented with melatonin.
박세관(Sea Kwan Park),박학열(Hak Youle Park),문교철(Kyo Cheol Mun),김여희(You Hee Kim),곽춘식(Chun Sik Kwak) 대한소화기학회 2002 대한소화기학회지 Vol.40 No.4
Background/Aims: To know the metabolism of oxygen free radicals in the regenerating liver, the 70% (median and left lateral lobes) partial hepatectomy was performed in the Sprague-Dawley rats. Methods: The original livers were obtained immediately after the partial hepatectomy, while the regenerating livers were obtained at 3 days after the partial hepatectomy. The levels of xanthine oxidase, superoxide anion, antioxidant enzymes, hydrogen peroxide, and malondialdehyde were measured. RT-PCR for superoxide dismutase was also performed. Results: Compared to the original livers, the regenerating liver showed higher levels of xanthine oxidase, superoxide dismutase, catalase, glutathione peroxidase superoxide production, and malondialdehyde and lower level of hydrogen peroxide. RT- PCR did not show any significant change. Conclusions: The results suggest that malondialdehyde level is increased by xanthine oxidase via the increased production of superoxide anion. Superoxide dismutase activity is induced by the increase of superoxide anion. The increase of catalase and glutathione peroxidase levels causes the depletion of hydrogen peroxide level in the regenerating liver. (Korean J Gastroenterol 2002; 40: 255-262)
시안산에 의한 조골세포의 손상에서 아미노산과 알부민의 효과
박경대 ( Kyung Dae Park ),박성배 ( Sung Bae Park ),최혜정 ( Hye Jung Choi ),문교철 ( Kyo Cheol Mun ),김현철 ( Hyun Chul Kim ) 대한신장학회 2007 Kidney Research and Clinical Practice Vol.26 No.4
Purpose : Cyanate, known as one of the uremic toxins and derived spontaneously from urea, has several effects on the biologic substances including erythropoietin, antioxidant and ceruloplasmin. To find out the protective materials from the hazardous effect of cyanate in osteoblast, we added twenty amino acids, albumin globulin and hemoglobin in the culture media containing osteoblastic cells with cyanate. Methods : Osteoblastic ROS 17/2.8 cells, exposed to various concentrations of sodium cyanate, were used to analyze for the cytotoxicity. The cyanate-induced cytotoxicity was assessed by the methylthiazolyldiphenyl -tetrazolium bromide (MTT) assay by measuring the absorbance of the reaction solution at 570 nm. Viability of the treated cells was expressed as A570 of sample/A570 of control. The degree of the carbamylation was measured using trinitrobenzenesulphonic acid. The degree of the carbamylation in amino acid was about 50% in average. Results : The degree of the carbamylation in albumin was increased depending on the incubation time with cyanate and the concentration of the cyanate. The degree of the carbamylation in globulin and hemoglobin was nearly zero. Asp, Glu, Leu, Trp and Tyr among the twenty amino acids revealed the protective effect against the damage induced by cyanate. And only albumin among the three proteins revealed the protective effect. Conclusion : On the basis of these results, Asp, Glu, Leu, Trp, Tyr and albumin are useful tools for the protection against damages by cyanate carbamylation.