The main purpose of this study is to evaluate the levels of inflammatory factors and vascular protective factors in streptozotocin (STZ)-induced diabetic rats and determine whether 1,25-D3 can protect the rat brains from hyperglycemia through the glucagon-like peptide-1 (GLP-1)R/PI3K/AKT signal pathway. This evidence concerns the gene GCG and Hyperglycemia.