Manipulation of Transmembrane Transport by Synthetic K+ Ionophore Depsipeptides and Its Implications in Glucose-Stimulated Insulin Secretion in ß-Cells.

The cyclic depsipeptide cereulide toxin it is a very well-known potassium electrogenic ionophore particularly sensitive to pancreatic beta cells. The mechanistic details of its specific activity are unknown. Here, we describe a series of synthetic substituted cereulide potassium ionophores that cause impressive selective activation of glucose-induced insulin secretion in a constitutive manner in rat insulinoma INS1E cells. Our study demonstrates that the different electroneutral K+ transport mechanism exhibited by the anionic mutant depsipeptides when compared with classical electrogenic cereulides can have an important impact of pharmacological value on glucose-stimulated insulin secretion.