PKC-Dependent Stimulation of Exocytosis by Sulfonylureas in Pancreaticβ Cells

Science  09 Feb 1996:
Vol. 271, Issue 5250, pp. 813-815
DOI: 10.1126/science.271.5250.813


Hypoglycemic sulfonylureas represent a group of clinically useful antidiabetic compounds that stimulate insulin secretion from pancreatic β cells. The molecular mechanisms involved are not fully understood but are believed to involve inhibition of potassium channels sensitive to adenosine triphosphate (KATP channels) in the β cell membrane, causing membrane depolarization, calcium influx, and activation of the secretory machinery. In addition to these effects, sulfonylureas also promoted exocytosis by direct interaction with the secretory machinery not involving closure of the plasma membrane KATP channels. This effect was dependent on protein kinase C (PKC) and was observed at therapeutic concentrations of sulfonylureas, which suggests that it contributes to their hypoglycemic action in diabetics.

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