[Establishment of high-fat diet-induced obesity and insulin resistance model in rats].
X Y Zhang, Caixia Guo, Yang Yu, L. Xie, Cuiqing Chang
Abstract
OBJECTIVE: To investigate the appropriate conditions and duration for establishing a high-fat diet-induced obesity and insulin resistance model in rats. METHODS: Forty-five 6-week-old male Sprague-Dawley (SD) rats were randomly assigned into 2 groups: (1) control group (CON), (2) high-fat diet group (HFD). HFD was fed with a high-fat diet (45% kcal from fat) while CON with chow diet. After four-weeks of high-fat diet feeding, the rats of obesity resistance (OR) were eliminated according to body weight sorting, whereas obese (OB) rats were continued feeding a high-fat diet until 12 weeks. Body weight and food intake were recorded weekly. Glucose tolerance was evaluated by oral glucose tolerance test (OGTT) in 4 weeks, 8 weeks and 12 weeks. At the end of 12 weeks, insulin releasing test and visceral fat mass were measured and HE staining of the liver, adipose tissue and pancreatic tissue were conducted. RESULTS: =0.008). Pathological changes were observed in islets and liver in the OB rats. CONCLUSION: After 4 weeks of a high-fat diet (45% kcal from fat) feeding in six-weeks SD rats, the rats of OR were eliminated. Impaired glucose tolerance was found in OB rats after 4 weeks of feeding, and the rate was higher after 8-12 weeks of high-fat diet feeding.