The Difference δ-Cells Make in Glucose Control.

The role of beta and alpha-cells to glucose control are established, but the physiological role of delta-cells is poorly understood. Delta-cells are ideally positioned within pancreatic islets to modulate insulin and glucagon secretion at their source. We review the evidence for a negative feedback loop between delta and beta-cells that determines the blood glucose set point and suggest that local delta-cell-mediated feedback stabilizes glycemic control.