A new model of type 2 (non-insulin-dependent) diabetes mellitus in spontaneously hypertensive rats: diabetes induced by neonatal streptozotocin treatment.

This study was designed to develop an animal model of Type 2 (non-insulin-dependent) diabetes with persistent hypertension. Male spontaneously hypertensive rats were treated with 25.0, 37.5, 50.0, 62.5 or 75.0 mg/kg of streptozotocin given intraperitoneally at 2 days of age and maintained for 12 weeks. In the rats which received 50.0 mg/kg or more streptozotocin, overt hyperglycaemia gradually and consistently developed following incomplete recovery from an initial hyperglycaemia. Compared to vehicle-treated controls, body weight gain in these animals did not differ for the first 8 weeks; thereafter, it was slightly but significantly (p less than 0.05) reduced. The animals treated with 25.0 or 37.5 mg/kg streptozotocin developed mild to moderate hyperglycaemia, but their body weight gain was similar to controls. The relationships between streptozotocin dose and metabolic responses (plasma glucose, glycosylated haemoglobin, urinary glucose, food intake, etc.) were clearly demonstrated. Systolic blood pressure rose with progressing age in both controls and streptozotocin-treated rats, irrespective of dosage or metabolic response. This new rat model of Type 2 diabetes associated with persistent hypertension may be useful in studying these combined effects on small and large vessels.