Fig. 3.

Aldosterone decreases insulin secretion in a dose-dependent manner in isolated islets and the MIN6 beta cell line. a Aldosterone reduced glucose-stimulated insulin concentrations, assessed as insulin secreted after 16.7 mmol/l glucose stimulus for 30 min in static culture (grey bars). Total islet insulin content was unaltered by aldosterone (white bars), suggesting an effect on insulin secretion rather than insulin content. b In MIN6 cells, aldosterone decreased insulin secretion in response to 23 mmol/l glucose (grey bars), reaching maximal inhibition at 100 nmol/l. c In isolated islet perifusion studies, insulin secretion in response to glucose (16.7 mmol/l) and isobutyl-methylxanthine (IBMX; 100 µmol/l) was diminished in the presence of aldosterone 1000 nmol/l (triangles) compared with control (circles). d Insulin secretion quantified as insulin AUC was significantly lower in islets treated with aldosterone (1000 nmol/l) in response to glucose (16.7 mmol/l) and (e) to glucose (16.7 mmol/l)+IBMX (100 µmol/l). *p≤0.05 and ***p≤0.001 vs 0 nmol/l aldosterone