Gain-of-function mutations in the Kir6.2 and SUR subunits of the KATP channel are associated with neonatal diabetes (ND). I used a mouse model selectively expressing the Kir6.2-V59M mutation in pancreatic β-cells (inducible iβ-V59M) to compare the effects of sulphonylurea and insulin therapy on neonatal diabetes. Gene expression was induced in adulthood, which caused severe hyperglycaemia and resulted in a major decrease in insulin content, pancreatic β-cell area, pancreatic islet number, ...