[Electrophysiological studies of insulin secretion, physiology and pathophysiology]

Recent progress in experimental diabetes research is reviewed in this article. The application of the patch-clamp technique to the insulin-secreting pancreatic beta-cell has revolutionised our understanding of how an increase in the blood glucose concentration is linked to stimulation of insulin secretion. A major advance was the identification of an ATP-regulated K-channel (KATP-channel) as the glucose-sensitive membrane conductance of the beta-cell. Closure of these channels underlies the glucose-induced depolarisation of the beta-cell, which then triggers the opening of voltage-gated Ca(2+)-channels and the onset of Ca(2+)-dependent exocytosis. With the patch-clamp technique, it was also possible to demonstrate that the KATP-channel represents the molecular target of the hypoglycaemic sulphonylureas, compounds which are used clinically in the treatment of type 2 diabetes.