hormone
Insulin
Insulin is a pancreatic hormone that helps regulate blood glucose and nutrient storage.
In muscle and fat, insulin signalling increases GLUT4 at the cell surface; the liver responds through related but distinct pathways.
A signal with tissue-specific effects
Pancreatic beta cells release insulin when blood glucose rises. Insulin binds its receptor and activates intracellular signalling; in muscle and fat this moves GLUT4 transporters to the cell surface, increasing glucose uptake. The liver handles glucose through distinct pathways and transporters.
Roles and processes
Pancreas produces Insulin
Beta cells in pancreatic islets make insulin. The pancreas releases insulin when blood glucose rises after eating.
Insulin helps glucose enter Insulin-responsive tissues
Insulin signalling increases GLUT4-mediated glucose uptake in muscle and fat and also changes how the liver handles glucose.
Related topics
Worth knowing
Insulin is one regulator. Insulin works alongside glucagon and other signals. The liver, muscle and fat tissue respond in different ways to help regulate blood glucose.
A closer look
The receptor and transporter are different
The insulin receptor starts the signal, while GLUT4 is the transporter whose placement changes in responsive tissues.
Glucose dependence has context
Insulin secretion and tissue responses vary with glucose, other nutrients, hormonal signals and tissue type.
References
Source-checked local draft.
Human editorial review pending.
- NIH National Institute of Diabetes and Digestive and Kidney DiseasesInsulin Resistance & PrediabetesChecked 2026-09-05
- World Health OrganizationDiabetes fact sheetChecked 2026-09-05
- NIH National Library of MedicinePhysiology, Glucose Transporter Type 4Checked 2026-09-05
- NIH National Library of MedicinePhysiology, Endocrine HormonesChecked 2026-09-05
- NIH National Library of MedicinePhysiology, Appetite And Weight RegulationChecked 2026-09-05