Effect of an alpha-glycosidase inhibitor on experimentally-induced obesity in mice

The effect of prolonged treatment with acarbose, an inhibitor of alpha-glycosidase, has been studied in mice made obese and hyperinsulinaemic by goldthioglucose. After the onset of obesity, one month after goldthioglucose administration, mice were then treated, with or without a 10% sucrose supplement, for four months with acarbose, added to the diet at 50 mg/100 g food. When mice received a standard diet, acarbose had no effect on body weight, blood glucose or insulin levels. In contrast, in the control obese mice receiving a 10% sucrose-enriched diet, it decreased the body weight gain, and prevented the rise in glycaemia and insulinaemia. Basal (non insulin-stimulated) glucose uptake, which is decreased in isolated soleus muscle from untreated obese mice, returned to normal values under acarbose treatment. However, muscle insulin resistance was not improved in acarbose-treated obese mice at maximal and submaximal effective concentrations, despite a higher insulin binding in muscles of acarbose-treated obese than in control obese animals. Furthermore, insulin receptor autophosphorylation and tyrosine kinase activity were altered similarly in treated and untreated obese mice compared to lean mice.