RESUMO
Objective To explore an optimal method of producing STZ-induced type 1 diabetic KM mice model by investigating the molded rate of single high dose and multiple low dose of STZ injection.Methods Sixty KM mice were randomly divided into 4 groups(n=15), two control groups and two model groups.In the two control groups, one was blank control and the other was negative control.Mice in the blank control group treated with no injection, but mice in the negative control group were treated with injection of citric acid salt buffer.For the two model groups, one was single high-dose group, 150 mg/kg STZ was injected only once.The other was multiple low-dose group, 50 mg/kg STZ was injected for 5 consecutive days.After the last injection, daily food and water intake were tested, blood glucose level and body weight were examined once a week for 4 consecutive weeks. Results Mice in the two model groups showed typical features of diabetes.The blood glucose levels in the two model groups were significantly higher than in the two control groups ( P <0.05 ) .For the two model groups, the molded rate of 150 mg/kg and 50 mg/kg group were 60% and 53.33%respectively at 1st week, but at the 4th week, they were 60% and 80% respectively.The mortality of these two groups at the 4th week was 33.33% and 20% respectively.Moreover, the blood glucose level in multiple low-dose group increased stably from the 2nd week to the 4th week.Conclusion The multiple low-dose STZ injection (50 mg/kg for 5 consecutive days) is an optimal method for producing KM mice model of type 1 diabetes mellitus.