Amelioration by KRP-297, a new thiazolidinedione, of impaired glucose uptake in skeletal muscle from obese insulin-resistant animals

We examined the effect of KRP-297, a new thiazolidinedione derivative, on glucose uptake in the soleus muscle of two animal models of insulin resistance that show moderate (obob mice) and severe (dbdb mice) hyperglycemia. Insulin-stimulated 2-deoxyglucose (2DG) uptake in soleus muscle was 53.8% lower in obob mice versus lean mice (P < .05). When administered to obob mice, KRP-297 (0.3 to 10 mg/kg) decreased plasma glucose and insulin levels and improved the impaired insulin-stimulated 2DG uptake in soleus muscle in a dose-dependent manner. Soleus muscle from dbdb mice exhibited defects in both basal (35.0% decrease P < .01) and insulin-stimulated (50.5% decrease, P < .01) 2DG uptake. These defects were improved by treatment with KRP-297 (0.3 to 10 mg/kg). Moreover, KRP-297 prevented severe hyperglycemia and the marked decrease in pancreatic insulin content in dbdb mice. These results suggest that KRP-297 treatment is useful to prevent the development of diabetic syndromes in addition to ameliorating the impaired glucose transport in skeletal muscle.