Abstract: AIM: To compare the classical diabetic db/db mice and another diabetic mice which were established by high-fat diet along with STZ injection for evaluating the two diabetic mice on the diabetes characteristic and the reaction to three different kinds of hypoglycemic drug.METHODS: After weaning male BALB/c mice fed with high-fat diet for 4 weeks, streptozocin(STZ)45 mg/kg were intraperitoneal injected once a day and consecutive three days.One week after the last injection, the fasting blood glucose and glucose tolerance were measured. The STZ diabetes mice were prepared successfully as their impaired glucose tolerance accompanying with fasting glucose higher than 8.0 mmol/L. The fasting blood glucose and glucose tolerance of the 8 weeks old db/db mice were also measured.The db/db mice and the STZ diabetes mice were divided into four groups randomly, treated with rosiglitazone(12 mg/kg),glibenclamide (45 mg/kg),insulin (1 U/kg) and normal saline once a day respectively.After four weeks,biochemical indexes and hormone level related to glucose and lipid metabolism were measured from the samples of the two diabetes models.RESULTS: Compared with the BALB/c normal mice, the fasting blood glucose,total cholesterol and triglycerides in STZ model mice were significantly increased(P<0.05) as well as the glucose tolerance was badly impaired, the serum insulin and c-peptide decreased significantly (P<0.05).Compared with the C57BL mice, the fasting blood glucose,total cholesterol,triglyc erides,the serum insulin and the c-peptide lever of db/db mice were all increased significantly (P<0.05)along with the impaired glucose tolerance.In the STZ experiment mice, rosiglitazone, glibenclamide and insulin decrease the fasting blood glucose and improve impaired the glucose tolerance significantly.In the db/db mice, only rosiglitazone can decrease their fasting blood glucose and improve impaired the glucose tolerance, but there was no change after treated with common dose of glibenclamide and insulin until tripling dose of insulin.CONCLUSION: The characteristics of the STZ diabetes mice induced by high-fat diet and multiple low-dose STZ injection were higher achievement ratio, the stable and lasting diabetes characters.The STZ diabetes mice were sensitive to a variety of different hypoglycemic drugs. db/db mice show severe insulin resistance blunting with endogenous and exogenous insulin.db/db mice show only the same sensitive to rosiglitazone as that of the STZ diabetes mice.

Key words: Diabetic mice model, db/db mouse, STZ diabetic mouse, Hypoglycemic drug