Diet-induced diabetes in the sand rat (Psammomys obesus).

Insulin deficiency is the underlying cause of hyperglycemia in type 2 diabetes. The gerbil Psammomys obesus (P. obesus) is a naturally insulin resistant rodent with tendency to develop diet-induced hyperglycemia associated with obesity. P. obesus does not exhibit hyperglycemia in its natural desert habitat, feeding on low caloric vegetation. However, when fed regular laboratory chow containing higher caloric density, the animals develop moderate obesity and hyperglycemia. Diabetes development and progression is very fast in P. obesus. The animals reach the irreversible hypoinsulinemic stage of the disease, in which a marked reduction of ß-cell mass is apparent, within 4-6 weeks of high caloric diet. The present review describes the P. obesus of the Hebrew University colony, with emphasis on its use for the study of ß-cell dysfunction in type 2 diabetes.