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Melatonin improves metabolic syndrome induced by high fructose intake in rats
Author(s) -
Kitagawa Akira,
Ohta Yoshiji,
Ohashi Koji
Publication year - 2012
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/j.1600-079x.2011.00955.x
Subject(s) - medicine , endocrinology , insulin resistance , melatonin , triglyceride , leptin , fructose , insulin , adiponectin , metabolic syndrome , insulin tolerance test , glucose tolerance test , lipid peroxide , uric acid , biology , cholesterol , diabetes mellitus , oxidative stress , lipid peroxidation , obesity , biochemistry , insulin sensitivity
In this study, we examined whether melatonin improves metabolic syndrome induced by high fructose intake in male Wistar rats. Feeding of a diet containing 60% fructose (HFD) for 4 or 6 wk caused increased serum insulin, triglyceride, total cholesterol, free fatty acids, uric acid, leptin, and lipid peroxide concentrations as well as hepatic triglyceride and cholesterol concentrations, and relative intra‐abdominal fat and liver weights. The 4‐ or 6‐wk HFD feeding reduced serum high‐density lipoprotein cholesterol and adiponectin concentrations. The 6‐wk HFD feeding increased serum tumor necrosis factor‐α concentration and hepatic lipid peroxide concentration and lowered hepatic reduced glutathione concentration. Daily intraperitoneal administration of melatonin (1 or 10 mg/kg body weight), starting at 4‐wk HFD feeding, attenuated these changes at 6‐wk HFD feeding more effectively at its higher dose than at its lower dose. In an oral glucose tolerance test, rats with 4‐ or 6‐wk HFD feeding showed higher serum insulin response curve and normal serum glucose response curve when compared with the corresponding animals that received the control diet. The 4‐ or 6‐wk HFD feeding caused insulin resistance, judging from the scores of HOMR‐IR and QUICKI, which are indices of insulin resistance. The daily administered melatonin (1 or 10 mg/kg body weight) ameliorated the higher serum insulin response curve in the oral glucose tolerance test and insulin resistance at 6‐wk HFD feeding more effectively at its higher dose than at its lower dose. These results indicate that melatonin improves metabolic syndrome induced by high fructose intake in rats.