Defective Glucose-Stimulated Insulin Release from Perifused Islets of C57BL/6J Mice

Previous work has shown that the C57BL/6J (BL/6) mouse strain develops type 2 diabetes after being fed a high-fat, high-simple carbohydrate (HFHSC) diet. In contrast, the AJ mouse strain does not. The aim of the present study was to determine if differences in the insulin secretory characteristics of isolated perifused islets of these animals could help explain why the BL/6 mouse develops diet-induced diabetes. Insulin secretion was assessed as mean integrated area under the curve during 20 min of stimulation with 27.7 mM glucose or 5 mM lauric acid. We found that both glucose- and laurate-stimulated insulin secretions were significantly less in euglycemic BL/6 mice than in the euglycemic AJ mice. The defect in insulin response to glucose, but not laurate, in islets from the BL/6 mouse was exacerbated when the animals were fed the HFHSC diet. These data suggest that the BL/6 mouse has a defective insulin response to glucose, which is exacerbated by a diabetogenic diet.