What hormone, secreted by K-cells, has an insulin incretin effect?

The hormone that has an insulin incretin effect and is secreted by K-cells is glucose-dependent insulinotropic peptide (GIP). This hormone plays a crucial role in the regulation of glucose metabolism by enhancing insulin secretion from the pancreas in response to glucose intake.

When you eat, GIP is released from the K-cells in the intestinal mucosa. It acts on pancreatic beta cells to promote insulin release, even before blood glucose levels rise significantly. This enhances the body's ability to manage and lower blood sugar levels after meals. Furthermore, GIP also plays a role in promoting fat storage and affects gastric motility, contributing to the overall metabolic process.

In the context of glucose homeostasis, GIP’s incretin effect is particularly important as it not only stimulates insulin secretion but also exhibits a synergistic effect with other incretin hormones like GLP-1 (glucagon-like peptide-1). This means that GIP is integral to the overall incretin effect seen in digestion, as incretins enhance insulin response during the postprandial state (after meals).

The other hormones listed do not exhibit the same incretin effect. For example, glucagon primarily functions to raise blood glucose levels, while cholecystokinin (