In the present study, we adopted single high-dose (60 mg/kg, i.p.)streptozotocin (STZ) to model diabetes mellitus (DM) and randomly assigned short-tail (SD) rats to a normal group, a diabetic group, GLP1 groups (50 μg/kg, 100 μg/kg, and 200 μg/kg), a GLP1 (200 μg/kg) with exendin (9-39) group, and a GLP1 with LY294002 group. The gene discussed is GCG; the disease is diabetes mellitus.