RESUMO
BACKGROUND: Food restriction has been reported to ameliorate diabetes and obesity. In this study, we examined the effects of the food restriction on phenotypes of TALLYHO/JngJ (TH) mouse, a recently developed diabetic model animal. METHODS: 3 week-old TH mice were divided into 2 groups (n = 20 each for food-restricted (THR) and free-fed (THF)) and THR mice were fed the same amount of food as normal control mice (C57BL/6, n = 20). Body weight was weekly monitored till 14 weeks of age. The half of animals were sacrificed at 8 weeks of age, and liver, kidney, and fat weight were measured. The histopathology of liver and brown fat tissues and mRNA expression of leptin in adipose tissue were analyzed. The oral glucose tolerance test and insulin resistance test was done at 14 weeks of age. The plasma concentrations of glucose, free fatty acid, triglyceride, cholesterol and leptin were analyzed. RESULTS: The THR mice had lower body weights than the THF mice, similar to C57BL/6 mice, with reduced fat deposition in liver and brown fat tissue. The plasma levels of glucose, triglyceride and free fatty acid were decreased in the THR group. The THR mice, however, carried more fat than normal mice, with increased plasma leptin concentration and leptin mRNA expression in fats and no alteration in plasma cholesterol levels. Furthermore, the THR mice revealed glucose intolerance with impaired after-meal insulin secretion and slight insulin resistance CONCLUSION: The food restriction apparently ameliorated the obesity and diabetic phenotypes of TH mice. However, plasma concentration of cholesterol were not improved in THR mice with increased adiposity index and glucose intolerance, suggesting the genetically prone tendency of obesity and diabetes development in TH mice possibly with an impairment in cholesterol metabolism.