[Relationship between structural and functional changes of islets, and abnormal metabolism of glucose and lipids in OLETF rats with impaired glucose tolerance].

OBJECTIVE: To investigate the level of blood glucose, cholesterol (Cho), triglycerides (TG), insulin secretion and the efficacy of acarbose in preventing impaired glucose tolerance (IGT) in Otsuka Long-Events Tokushima Fatty (OLETF) rats. METHODS: 10 OLETF rats with IGT, 8 IGT OLETF rats with acarbose treatment, and 36 LETO rats with normal glucose level were observed for their blood glucose, Cho, TG, insulin secretion and histological changes in the pancreas and skeletal muscles. RESULTS: OLETF rats with IGT were mild obese, with fat infiltration in the islets and skeletal muscles. Their blood Cho and TG were higher than those of LETO rats (2.5 mmol/L +/- 0.3 mmol/L vs 2.1 mmol/L +/- 0.3 mmol/L, P < 0.01; 0.7 mmol/L +/- 0.2 mmol/L vs 0.4 +/- 0.2 mmol/L, P < 0.01), but their TG was lower than that of diabetic rats (1.8 +/- 1.0). The Cho, TG and post-challenge glucose levels were normal in the IGT rats with 4-week acarbose treatment, with their insulin secretion and glucose tolerance improved and fat infiltration decreased. CONCLUSION: Acarbose can prevent obesity and fat infiltration in islets and muscles, improve glucose and lipid metabolism, and insulin secretion in OLETF rats with IGT.