REPEATED LOW-DOSE STREPTOZOTOCIN ADMINISTRATION AFTER HIGH FAT DIET AND HIGH FAT DIET-SUCROSE TREATMENTS PRODUCE ROBUST ANIMAL MODELS FOR TYPE-2-DIABETES MELLITUS

Introduction: The high mortality rate and extensive technical know-how required for developing and handling genetically-modified animal models has given basis to the alternative use of chemicals for induction of diabetes in laboratory animals. However, data on standardized methodology for chemical induced type-2-diabetes in animals is inadequate. This study seeks to explore the robustness of diet-chemical combination for inducing type-2-diabetes in male wistar rats.

Methodology: Twelve-weeks old male Wistar rats were randomly selected into 3 groups (I, II, and III) and fed Normal chow, High fat diet (HFD), and High fat diet + sucrose tonic (10g/250ml) ad libitum respectively for 10 weeks followed by two doses of 35mg/kg body weight of streptozotocin (STZ) injection intraperitoneally at three days interval. Three milliliters (3ml) blood samples were drawn a week after the last dose of STZ-administration and biochemical measurements were determined. Numerical data was tabulated and expressed as mean Standard error of mean. The students t-test and one-way Anova were used to compare differences between common variables measured between the groups. P-value < 0.5 was considered significant.

Results: The group II had a significantly elevated body weight compared to the groups I and III. The groups II and III animals treated with low dose-STZ had significantly elevated diabetogenic indices including HOMA-B, HOMA-IR, OGTT and fasting blood glucose compared to the Normal controls (Group I). A 100% diabetes success rate was achieved among the groups II and III even after a week of STZ administration.