German: Betazelle
Definition
Insulin producing cells in pancreatic Langerhans-islands are referred to as beta cells. Beta cells amount as much as 80 percent of cell mass in pancreatic islands.
Physiology
Glucose that is absorbed and metabolized to ATP is the most important stimulus of insulin secretion from beta cells.Increased ATP concentration inhibits potassium channels in the cell membrane. Reduced potassium loss leads to depolarization of the cell membrane.
In the consequence voltage dependent calcium channels are activated that permit inflow of calcium thus mediating secretion of insulin.
Insulin is a potent antihyperplycemic and prohypoglycemic hormone thus closing the feedback loop that control blood glucose levels.
Diagnostical procedures
Beta cell function may be assessed primarily by oral glucose tolerance tests (OGTT) or intravenous glucose tolerance tests (ivGTT). Additional information is provided by advanced cybernetic methods like- Homeostasis model (HOMA)
- QUICKI
- Minimal model
- MiMe-NoCoDI model (SPINA)
