Diet-Induced Fatty Hepatic Steatosis in Male Spontaneously Diabetic Torii (SDT) Fatty Rats, A Genetic Model for Obese Type 2 Diabetes

Aim: The Spontaneously Diabetic Torii (SDT) fatty rat is a metabolic syndrome model, showing obesity, hyperglycemia, dyslipidemia, and hypertension. Moreover, female SDT fatty rats exhibit hepatic steatosis. In this study, metabolic abnormalities, particularly in the liver, were assessed in male SDT fatty rats fed a diet containing 40% fat and 2% cholesterol (HFC-diet).
Location and Duration of Study: Niigata University, CLEA Japan and JT Central Pharmaceutical Research Institute, between January and December 2014.
Methodology: Male SDT fatty rats in control and HFC groups were fed a standard or HFC-diet (40% fat and 2% cholesterol, based on percentage of total calories) from 5 to 17 weeks of age, respectively. Body weight and blood chemistry parameters were periodically measured and a pathological analysis of the liver was performed at 17 weeks of age.
Results: In biological analyses, the HFC group showed increases in body weight, blood insulin, and total cholesterol during the experimental period and an increase in aspartate aminotransferase (AST) at 13 weeks of age. Blood glucose levels in HFC group decreased after 13 weeks of age. In pathological examinations, an increase in liver weight and hepatic steatosis, fatty change and hypertrophy in hepatocyte, were observed in the HFC group. Hepatic steatosis was not observed in the standard-diet group.
Conclusion: Male SDT fatty rats fed an HFC-diet may serve as a new nonalcoholic fatty liver disease (NAFLD) model.