What are the islets of Langerhans?
Langerhans arets are clusters of cells in the pancreas that produce different hormones. They are named for German pathologist Paul Langerhans, who first observed them in 1869. A healthy human pancreas contain approximately one million of these cells, but their total weight is only 1 to 1.5 grams (0.03 to 0.05 ounces) or about 1% of the pancreatic weight. The rest of the pancreas are used to produce enzymes that help in food digestion, while Langerhans islands produce hormones that help regulate the sugar level, also called glucose, in the blood. Beta cells are most common and make up about 65 to 80% of total islets. Beta cells are responsible for making hormones of insulin and amylin.
Insulin is a primary hormone involved in blood glucose levels. It stores excess sugar in tissues in tform glycogen and prevents blood glucose levels to become too increased. Damage to beta cells producing insulin in islands is one of the primary causes of type 1 diabetes.
Beta cells in Langerhans are also produced hormone amylin. Amylin slows down the stomach emptying after a meal. It also works with insulin to reduce blood glucose.
alpha cells make up approximately 15 to 20% of these cellular clusters and produce hormonal glucagon. When blood glucose levels are too low, the glucagonian signals the liver to convert the stored glycogen into glucose and release it into the bloodstream. Glukagon and insulin work against each other to maintain blood glucose levels under control.
about 3 to 10% of Langerhans islands consists of delta cells that produce somatostatin. Somatostatin is not understood just like insulin and some of the hormones, but it is believed to slow the stomach emptying, inhibits some gastrointestinal hormones and works with glucagon against the release of too much insulin.
The rest of the cells in the islands is made up of epsilon cellme. These cells produce the cells of the hungry hormone ghrelin and pancreatic polypeptides (PP) that regulate the secretions that the pancreas create. Epsilon and PP cells are not well understood.
Cell transplantation from Langerhans islands has been explored as a possible way to control or even treat diabetes, especially type 1.