The mechanism of insulin-improved fatty liver in STZ-induced diabetes male rats

• Main Authors: Lin, Ting-Wen, 林亭妏
• Other Authors: Tsai, shiow-Chwen
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/q2b72k

碩士 === 臺北市立大學 === 運動科學研究所 === 106 === Purpose: (1) Observe whether insulin could improve diabetes in liver, and oxidative stress or antioxidant capacity level after acute exercise challenges. (2) Observe whether the insulin treatment had equal efficacy in the old rats. Method: There were two experiment in this study. Study one: 18 weeks old rats injected STZ to induce diabetes, insulin treatment, and down heel running at the last of the experiment. Rats were divided to control group (C), diabetes group (S), diabetes plus insulin (SI), control with down heel running (EC), diabetes with down heel running (ES), diabetes plus insulin with down heel running (ESI). Study two: 22 months old rats injected STZ to induce diabetes, and insulin treatment. Rats were divided to control group (OC), diabetes group (OS), diabetes plus insulin (OSI). After one week acclimation, rats were individually injected with sodium citrate (also referred to as STZ carrier) or STZ, and fasting blood glucose was measured with a blood glucose meter. When the blood glucose level was 300 mg/ dL or more, they were injected twice daily saline or insulin (0.25 IU/ml). Feeding a total of 14 days, pentobarbital (40 mg/kg) was anesthetized before injection of STZ and at the end of the feeding period. Testing body composition by DEXA, then sacrifice and take the liver and perirenal fat to assay for the production of TBARS and Glutathione. Hematoxylin and eosin stain will be used to determine liver steatosis and size of perirenal fat cell, and Masson's staining will be used to determine fibrosis. Data were analyzed statistically by two-way ANOVA. Post-hoc were performed one-way ANOVA and Bonferroni multiple tests to differentiate the effect of S and SI group. P<0.05 were considered as significant difference. Independent-sample T test was used to differentiate the effect of young and old/ young and exercise groups. P<0.05 were considered as significant difference. Result: Aging and diabetes would cause weight loss. Diabetes in the elderly would cause a rapid decline in lean mass, insulin treatment would slow down the loss of fat after STZ injection. Histological in liver produced more vacuolation in elderly diabetes. After an acute exercise challenge in young rats, the mechanism of antioxidant capacity of glutathione was upregulated. Both insulin treatment and acute exercise challenge can increase antioxidant capacity and decrease oxidative stress. Conclusion: Insulin treatment was effective in diabetes weight loss, acute exercise challenge contributed to increase antioxidant capacity, also with insulin treatment can decrease oxidative stress.