Chloride channels and transporters in β-cell physiology

Abstract

The ability of β-cells to depolarize, regulate [Ca 2+ ] i, and secrete insulin even in the absence of functional K ATP channels strongly suggests the presence of additional ionic cascades of events within the process of stimulus-secretion coupling. The purpose of this review is to introduce the reader to the role of the long-relegated and largely ignored subject of intracellular Cl − concentration ([Cl − ] i). The regulation of [Cl − ] i by transporters and channels, and their potential involvement in glucose-induced insulin secretion, is also discussed. It is important to keep in mind that, in the last decade, the molecular identification and functional characterization of many diverse regulators of [Cl − ] i in p-cells have added to the extraordinary complexity of the β-cell secretory response. We have therefore concentrated on key concepts, and on what we consider may be the most important players involved in the regulation of [Cl − ] in β-cells, but time will tell.