5-Hydroxytryptamine in the Endocrine Pancreas

The presence of serotonin (5-hydroxytryptamine [5-HT]) in pancreatic endocrine cells is well established. Nevertheless, recent advances are only now unraveling the signaling network involving 5-HT that partly regulates the release of hormones emanating from the islets of Langerhans. It is widely accepted that failure of the pancreatic β-cell to release sufficient amounts of insulin is the main culprit in the development of type 2 diabetes, an ongoing global epidemic. In this context, 5-HT signaling may play a crucial role. In fact, serotonin (5-HT) is part of an intricate signaling network regulating release of insulin and glucagon, the main hormones that control lipid and glucose homeostasis. Several studies have focused on the role of 5-HT and signaling through various 5-HT receptors in pancreatic β-cells and effects on overall glucose metabolism. Here, we aim to discuss some of these issues.