Nongenetic model of type 2 diabetes: a comparative study

Area of Science:

• Metabolic research
• Animal models of disease
• Endocrinology

Background:

• Developing reliable animal models is crucial for understanding type 2 diabetes.
• Existing models often have limitations in mimicking human disease progression.
• Comparing different induction methods helps optimize experimental designs.

Purpose of the Study:

• To evaluate the efficacy of high-fat (HF) diet plus streptozotocin (STZ) versus low-fat (LF) diet plus nicotinamide-STZ (NA-STZ) in creating a type 2 diabetes rat model.
• To identify the optimal STZ dosage in HF diet-fed rats for diabetes induction.
• To compare the physiological and metabolic outcomes between the different models.

Main Methods:

• Seven-week-old male Sprague-Dawley rats were assigned to six groups with varying diets (LF/HF) and STZ/NA-STZ induction.
• Diabetes was induced via intraperitoneal injection of NA-STZ or STZ at different doses (30, 40, 50 mg/kg BW).
• Blood glucose, serum insulin, serum lipid, and liver glycogen levels were measured post-induction.

Main Results:

• The HFD40 and HFD50 groups exhibited significantly elevated fasting and nonfasting blood glucose levels, indicative of diabetes.
• Serum insulin was significantly decreased in LFD, HFC, HFD30, and HFD40 groups.
• HFD groups showed increased serum lipid and liver glycogen; HFD50 group experienced critical conditions.

Conclusions:

• The high-fat diet combined with a 40 mg/kg BW STZ injection (HFD40) offers a superior model for human type 2 diabetes compared to the low-fat diet with NA-STZ.
• This model effectively induces hyperglycemia and metabolic changes relevant to type 2 diabetes.
• Careful selection of diet and STZ dosage is essential for establishing a robust and safe animal model.