Diabetes mellitus is the main risk factor for cardiovascular disease, which induces endothelial dysfunction and decreased angiogenesis in the cardiac tissue.20-22 In the present study, originally and for the first time, the combined IGF-I and exercise therapy’s impact on microvascular density (MVD), proteins involved in angiogenesis, and histological changes of the STZ-induced with insulin-dependent diabetes mellitus (Type I) rat model’s heart tissue were analyzed. The gene discussed is IGF1; the disease is endothelial dysfunction.