Insuliinieritystä

Insuliinieritystä refers to the process by which insulin is released from the beta cells of the pancreas. This process is crucial for regulating blood glucose levels. When blood glucose rises, for example after a meal, beta cells in the islets of Langerhans detect this increase. In response, they release insulin into the bloodstream.

Insulin acts as a key that unlocks cells, allowing glucose to enter from the blood and be used for energy or stored. This lowers blood glucose levels back to a normal range. The release of insulin is a complex process involving several steps within the beta cell. Glucose enters the beta cell, is metabolized, and this leads to the production of ATP. Increased ATP levels trigger the closure of ATP-sensitive potassium channels, causing depolarization of the cell membrane. This depolarization opens voltage-gated calcium channels, allowing calcium ions to enter the cell. The influx of calcium is the primary signal that stimulates the fusion of insulin-containing vesicles with the cell membrane, releasing insulin into the circulation.

Factors other than glucose, such as certain amino acids and hormones like incretins (GLP-1 and GIP), can also stimulate insulin secretion. Conversely, low blood glucose levels inhibit insulin release. Dysregulation of this process is central to the development of diabetes mellitus, where either insufficient insulin is produced or the body's cells do not respond properly to insulin.