Histological, ultrastructural and stereological analyses of pancreatic islets in glucocorticoid-treated rats

Abstract

Dexamethasone is a synthetic glucocorticoid commonly used in both human and veterinary medicine. Prolonged treatment with dexamethasone can lead to serious metabolic side effects such as insulin resistance and diabetes. In this study, the morphological, immunohistochemical, and ultrastructural changes in the rat pancreatic islets were investigated after dexamethasone treatment (2 mg/kg, intraperitoneally for 12 days). The results showed that the volume density, mean diameter and profile area of islets were significantly increased in dexamethasone-treated animals. The volume density, profile area and mass of B-cells increased, whereas the volume density of A-and D-cells decreased, as did the number of A-cells per mm 2 of islet. Mild insulin immunopositivity of the centrally located B-cells together with altered ultrastructural features indicated their loss of function. The results of the present study suggest adverse effects of dexamethasone on pancreatic endocrine function that may ultimately seriously affect glucose homeostasis.