Estrogen increases glucose-induced insulin secretion from mouse pancreatic islets cultured in a prolonged high glucose condition

Background: It is known that males are more susceptible to develop type 2 diabetes than females. Estrogen has a protective effect on pancreatic islet against toxic agent such as amyloid. The role of estrogen in protection pancreatic islet against high glucose is still unknown. Objective: Administration of estrogen in an ovariectomised animal shows a protective effect against type 2 diabetes. The present study aimed to determine the direct effect of estrogen on the islet function after prolonged culture in high glucose. Material and Method: Estrogen (10^-5 M in ethanol) was co-cultured with mouse pancreatic islets in normal glucose medium (11.1 mM) for 3 hours or with normal and high glucose medium (40 mM) for 10 days. Results: Estrogen increased glucose-induced insulin secretion in islet culture in normal glucose medium for both 3-hour and 10-day culture. Prolonged exposure of pancreatic islet to high glucose generated impaired glucose-induced insulin secretion, which was partially abrogated by the presence of 10^-5 M estrogen. Conclusion: These results indicated a direct effect of estrogen on improving insulin secretion from mouse pancreatic islets that has been impaired by prolonged exposure to high glucose.