New model of progressive non-insulin-dependent diabetes mellitus in mice induced by streptozotocin

This study was designed to clarify the relationship between streptozotocin (STZ) dosage (100, 150 and 200 mg/kg i.p.) and the resulting diabetogenic r esponse in mice (8-week-old male ICR). In this experiment, we found that a single i.p. injection of 100 mg/kg STZ is able to induce progressive diabet es mellitus, in which nonfasting serum glucose levels begin to rise from 3 weeks and continue to rise throughout the experimental period until 9 weeks . The non-fasting serum insulin levels of 100 mg/kg STZ-treated mice were n ormal during the experimental period. in addition, the population of insuli n-immunoreactive cells (beta cells) in the islets of pancreata was slightly less than in normal mice at 9 weeks. In 200 mg/kg STZ-treated mice, on the other hand, the insulin levels were below measurable values and insulin-im munoreactive cells were not observed. It is concluded from these results th at the progressive diabetic mouse model induced by a single i.p. injection of 100 mg/kg STZ, unlike 200 mg/kg STZ-induced diabetes which is insulin-de pendent, is non-insulin-dependent.