Liver and kidney commonly affected by diabetes in chronic cases but pathogenetic mechanisms are not fully understood in early stages of the disease. The aim of this study was to investigate the immunohistochemical expression of caspase-3, cyclooxygenase (COX)-1 and-2, calcium sensing receptor (CSR), and hypoxia inducible factor-1 alpha (HIF-1 alpha) in pancreas, liver, and kidney in streptozotocin (STZ) induced DM. Study group (n = 6) were received streptozotocin (50mg/kg) and control group (n = 6) physiologic saline. The blood glucose and ketonuria were measured, and necropsy was performed on them on third, fourth, and fifth days. Immunohistochemistry revealed that marked increase in caspase-3 reaction pancreas, liver, and kidney in the study group than control group. COX-1 slightly increased in these organs in study group compared to controls. Immunohistochemically COX-2 reaction was markedly positive in liver and kidney, but slightly increased in pancreas. The most increased reaction was observed in CRS and all organs were markedly positive. HIF-1 alpha expression was also increased but the reaction was more severe in pancreas than liver and kidney. This study indicated that degeneration starts in organs in early stages of the disease and the most effective route for degeneration related to increase of calcium influx and hypoxia upon cells in DM.