Characteristics of WBN/Kob diabetic fatty rats supplemented with a fructose-rich diet as a metabolic syndrome model: response to a GLP-1 receptor agonist

Pathophysiological Features of Rat Models of Nonalcoholic Fatty Liver Disease/Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) is caused by various factors, including genetic and/or environmental factors, and has complicated pathophysiological features during the development of the disease. NAFLD/NASH is recognized as an unmet medical need, and NAFLD/NASH animal models are essential tools for developing new therapies, including potential drugs and biomarkers. In this review, we describe the pathological features of the NAFLD/NASH rat models, focusing on the histopathology of hepatic fibrosis. NAFLD/NASH rat models are divided into three categories: diet-induced, genetic, and combined models based on diet, chemicals, and genetics. Rat models of NASH with hepatic fibrosis are especially expected to contribute to the development of new therapies, such as drugs and biomarkers.

Diagnostic Criteria for Metabolic Syndrome in Diet-Induced Rodent Models: A Systematic Review

BACKGROUND

Thousands of publications in recent years have addressed the induction of metabolic syndrome (MetS) in rodents. However, the criteria and the reference values for diagnosing this disease have not been defined.

OBJECTIVE

Our main objective was to carry out a systematic review to gather evidence about the criteria for biochemical and anthropometric parameters in which scientific studies have relied on to report that rats developed MetS from a previous dietary manipulation.

METHODS

We compiled characteristics and findings of diet-induced MetS with high-fat, high-carbohydrate, high-fat/high-carbohydrates, and cafeteria diet from PubMed and Science Direct databases published in the last 5 years.

RESULTS

The results on the principal determinants for the syndrome, published in the reviewed articles, were chosen to propose reference values in the rat models of food induction.

CONCLUSION

The values obtained will serve as reference cut-of points in the development of the disease; in addition, the compilation of data will be useful in planning and executing research protocols in animal models.

Effects of liraglutide on metabolic syndrome in WBN/Kob diabetic fatty rats supplemented with a high-fat diet

BACKGROUND

Liraglutide, a GLP-1 receptor agonist, has recently been used to treat metabolic syndrome (MS) because of its anti-diabetic and anti-obesity effects. We have previously shown that Wistar Bonn Kobori diabetic and fatty (WBN/Kob-Lepr fa , WBKDF) rats fed a high-fat diet (HFD) developed MS including marked obesity, hyperglycemia, and dyslipidemia. To obtain further information on WBKDF-HFD rats as a severe MS model, we performed a pharmacological investigation into the anti-MS effects of liraglutide in this model.

METHODS

Seven-week-old male WBKDF-HFD rats were allocated to three groups (N = 8 in each group): a vehicle group, a low-dose liraglutide group, and a high-dose liraglutide group. They received subcutaneous injections of either saline or liraglutide at doses of 75 or 300 μg/kg body weight once daily for 4 weeks.

RESULTS

Results showed that liraglutide treatment reduced body weight gain and food intake in a dose-dependent manner. The marked hyperglycemia and the glucose tolerance were also significantly ameliorated in the liraglutide-treated groups. Moreover, liraglutide also reduced the plasma triglyceride concentration and liver fat accumulation.

CONCLUSIONS

The present study demonstrated that liraglutide could significantly alleviate MS in WBKDF-HFD rats, and the reaction to liraglutide is similar to human patients with MS. WBKDF-HFD rats are therefore considered to be a useful model for research on severe human MS.