- Increased ROS Production by High Glucose in Cultured Mouse Insulinoma Cell Line.
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Jin Hwa Kim, Jung In Kim, Dong Hyun Choi, Young Uk Seo, Young Dae Kim, Jong Chan Oh, Beom Ju Lee, Keo Woon Park, Sang Yong Kim, Hak Yoen Bae, Byoung Rai Lee
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Korean Diabetes J. 2004;28(4):273-283. Published online August 1, 2004
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Abstract
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- BACKGROUND
To investigate the effects of high glucose on oxidative stress of islet beta cells, the effects of high glucose on antioxidant enzymes, the production of free reactive substances and paraquat-induced cytotoxicity were examined in cultured mouse insulinoma cells (MIN6N8a). METHODS: The MIN6N8a cell line (Obtained from Diabetic research center, Univer sity of Calgary, Canada) was maintained in RPMI1640 medium supplemented with 10% fetal bovine serum, at 37degrees C under an atmosphere of 5% CO2 and 100 % humidity. The MIN6N8a cells were cultured in high glucose (22.4 mM) and normogl-ucose (5.6 mM) containing RPMI1640 media, for 1-6 days, and the superoxide dismutase (SOD), catalase and glutathione peroxidase (GSHPx) activities in the MIN6N8a cells assayed. The levels of reactive oxygen species in the MIN6N8a cells was determined using dihydroethidium (DHE). Paraquatinduced cytotoxicity was determined using the 3-[4,5-dimethylthiazol-2-yl]-2, 5diphenyl tetraz olium bromide (MTT) method. RESULTS: No difference was observed catalase in the catalase and GSHPx activities in MIN6N8a cells between the high glucose (22.4 mM) and normoglucose (5.6 mM) groups. The CuZn-SOD activity of MIN6N8a cells was decreased by 32% in the high glucose (25.4 mM) medium compared to normoglucose (5.6 mM) medium, while the Mn-SOD activity was increased by 24% in high glucose group. The paraquat induced cytotoxicity of MIN6N8a cells was potentiated by high glucose. and the amount of DHE oxidation increased. CONCLUSION: The Oxidative stress in MIN6N8a cells was increased by high glucose as a resulted of the decreased CuZn-SOD activity and increased production of reactive oxygen species. Increased oxidative stress in MIN6N8a cells by high glucose may play some roles in the pathogenesis of diabetes.
- Effects of Gutathione on Cyclosporine A-induced Cyotoxicity in Cultured Rat Insulinoma (RIN5mF) Cells.
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Dong Hyun Choi, Byoung Rai Lee, Dai Yong Jang, Jong O Kim, Byung Soo Kim, Ki Young Chung, Tae Young Lim, Byung Chul Shin, Hak Yeon Bae
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Korean Diabetes J. 2002;26(1):58-64. Published online February 1, 2002
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Abstract
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- BACKGROUND
Cyclosporin A (CsA) is a immunosuppressive agent that is most widely used in organ transplanted patients to prevent immunorejection, However, it has some side effects, including diabetes mellitus, nephrotoxicity and hypertension. The mechanism of CsA cytotoxicity is unclear but it has been suggested that reactive oxygen species are involved in the cytotoxic reactions. The purpose of this study was to determine the effects of glutathione, as a physiological antioxidant on CsA induced beta-cell toxicity. METHODS: Rat insulinoma (RINm5F) cells were incubated with culture media (RPMI1640) in the presence of CsA and/or buthionine sulfoximine (BSO), which is an inhibitor of r-glutamyl cysteine synthetase, and reduced glutathione. The viable cells were examined using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and was determined by a spectrophotometer at a wavelength of 570 nm. RESULTS: Incubating the RINm5F cells with CsA resulted in a decrease in cell viability with increasing dose. This deceased cells viability, induced by CsA was potentiated by BSO treatment. The CsA and BSO induced cells toxicity was reduced significantly by the reduced glutathione. CONCLUSION: The results suggest that pancreatic beta-cell may be injured by CsA and glutathione may have some role in cytotoxicity.
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