Regarding histopathological and immunohistochemical findings, in previous studies (Komers et al. 2001; Ozmen et al. 2007), STZ induces severe and permanent DM with a decrease in insulin levels 3 days after STZ administration in mature rats to produce cytotoxic models of diabetes, which are very similar to T2DM. This evidence concerns the gene INS and type 2 diabetes mellitus.