Oscillatory control of insulin secretion

Pancreatic β-cells possess an inherent ability to generate oscillatory signals that trigger insulin release. Coordination of the secretory activity among β-cells results in pulsatile insulin secretion from the pancreas, which is considered important for the action of the hormone in the target tissues. This review focuses on the mechanisms underlying oscillatory control of insulin secretion at the level of the individual β-cell. Recent studies have demonstrated that oscillations of the cytoplasmic Ca2+ concentration are synchronized with oscillations in β-cell metabolism, intracellular cAMP concentration, phospholipase C activity and plasma membrane phosphoinositide lipid concentrations. There are complex interdependencies between the different messengers and signalling pathways that contribute to amplitude regulation and shaping of the insulin secretory response to nutrient stimuli and neurohormonal modulators. Several of these pathways may be important pharmacological targets for improving pulsatile insulin secretion in type 2 diabetes.