An animal model is described that can be used to detect drugs that may exacerbate or ameliorate diabetes. The design of this model is based upon the finding that hyperglycemia caused by intravenous administration of streptozotocin to rats is inversely correlated with pancreatic insulin concentration when expressed as total pancreatic insulin (ng) per body weight (g). Drugs that alter this relationship may be classified, in a preliminary manner, as ameliorative or diabetogenic.