Pancreatic β-cell metabolic pathways (GSIS)

Pancreatic β-cell metabolic pathways represent the integrated biochemical processes responsible for glucose-stimulated insulin secretion (GSIS), the primary mechanism for maintaining glucose homeostasis (PMID: 28844481). The process begins with glucose entry into the β-cell via GLUT transporters and its subsequent phosphorylation by glucokinase, which acts as the rate-limiting glucose sensor (PMID: 11316476). Mitochondrial metabolism of glucose-derived pyruvate increases the intracellular ATP/ADP ratio, which triggers the closure of ATP-sensitive potassium (KATP) channels (PMID: 15001617). This closure leads to membrane depolarization, opening of voltage-gated calcium channels, and a subsequent influx of Ca2+ that drives the exocytosis of insulin granules (PMID: 23512305). In type 2 diabetes, these metabolic pathways are often impaired, resulting in blunted insulin responses to glucose and chronic hyperglycemia (PMID: 21613668). Therapeutic agents like sulfonylureas and meglitinides target the KATP channels within this pathway to bypass metabolic defects, while newer agents like glucokinase activators aim to enhance the initial sensing step. Because this entry describes a complex system of pathways rather than a single molecular target, it is classified as a broad biological process.

Other names

Glucose-stimulated insulin secretion pathwayBeta-cell glucose metabolismStimulus-secretion couplingPancreatic beta-cell metabolic signaling

Modulation of ATP-sensitive potassium (KATP) channels or activation of glucokinase to enhance the coupling of glucose sensing to insulin exocytosis.