Streptozotocin (STZ) is used to induce experimental diabetes in rodents. There is however, controversy as to whether STZ induced diabetes models type 1 or 2 diabetes. We show that the grade of STZ-induced
hyperglycemia in male CD1 mice is dependent on STZ dose. A single injection of high dose (130 or 150 mg/Kg
body weight) or multiple
injections (2, 3, 4 or 5) of low dose (40 mg/Kg
body weight) STZ was administered intraperitonealy in non-fasted mice.
Blood glucose and
body weight were measured over 21 days for high dose and 21 and 28 days for low dose administration. On day three, high dose treatment produced
hyperglycemia and
body weight loss in comparison to mice without STZ, however unstable
hyperglycemias and several deaths were observed during treatment.
Hyperglycemia and
body weight loss were seen with three or more
injections of STZ at 21 days, whereas 4 and 5
injections produced severe
hyperglycemia but not death. Mild
hyperglycemia (250-450 mg/dL) was seen after 28 days following three
injections of STZ. Therefore we concluded that a high dose STZ produces severe
hyperglycemia in mice similar to a type 1 diabetic, and three successive administrations of STZ induces mild
hyperglycemia in mice similar to type 2 diabetics.