AIM To study the glucose and lipids metabolism and insulin sensitivity of MSG rats during their growing period, and to evaluate
the effects of insulin sensitizer pioglitazone on the model rats. METHODS Body weights were measured regularly, and glucose and insulin tolerance tests were taken. In their 3 and 10 months old, rats were given insulin sensitizer pioglitazone orally, then the effects on serum glucose, triglyceride, cholesteral, free fatty acid and insulin concentrations were determined. RESULTS Compared with normal rats, a slight but significant increase of glucose in MSG rats was revealed. The serum triglyceride, cholesteral, free fatty acid and insulin concentrations were
significantly higher in model rats. Moreover, gluconeogenesis increased significantly, and insulin tolerance showed abnormal. However, glucose tolerance was nearlly normal. Pioglitazone could ameliorate all these metabolic disorders. CONCLUSION Obesity and
insulin resistance were induced by injecting monosodi- um glutamate (MSG) to neonatal Wistar rats. Piogli- tazone can significantly improve the insulin sensitivity of Msc rats. These results suggested that MSG obese rats can be used as an easily accessible and inexpensive insulin resistance animal model for evaluating the efficacy and mechanisms of antidiabetic agents.