insulinewerking

Insulin action, sometimes referred to in non-English contexts as insulinewerking, denotes the physiological effects produced by insulin. Insulin is a peptide hormone produced by pancreatic beta cells that promotes glucose uptake and utilization in muscle and adipose tissue, suppresses hepatic glucose production, and regulates lipid and protein metabolism. The action of insulin helps maintain blood glucose within a narrow range after meals and during fasting.

Mechanism at the cellular level involves insulin binding to the insulin receptor, a receptor tyrosine kinase, on liver, muscle, and fat cells. Receptor autophosphorylation triggers signaling through IRS proteins and the PI3K-AKT pathway, leading to translocation of GLUT4 transporters to the cell membrane and increased glucose uptake in muscle and adipose tissue. In the liver, insulin inhibits gluconeogenesis and promotes glycogen synthesis. In adipose tissue, it stimulates lipogenesis and inhibits lipolysis; in muscle, it supports protein synthesis and amino acid uptake.

Pharmacological relevance encompasses differences among insulin formulations. Endogenous insulin and exogenous insulin preparations differ in onset, peak, and duration (rapid-acting, short-acting, intermediate-acting, long-acting). The metabolic actions include lowering blood glucose and promoting energy storage, while counterregulatory hormones such as glucagon, epinephrine, cortisol, and growth hormone oppose insulin effects.

Clinical considerations include insulin resistance, a hallmark of type 2 diabetes and metabolic syndrome, which reduces insulin action and necessitates therapeutic adjustment. Insulin therapy aims to restore effective action and prevent hyperglycemia but carries a risk of hypoglycemia. Exercise, obesity, illness, and certain medications can modify insulin sensitivity and action.

Research continues to refine understanding of insulin signaling networks and their interactions with other metabolic pathways, informing treatments for diabetes and metabolic diseases.