islets of Langerhans


Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
Related to islets of Langerhans: insulin, pancreas, somatostatin

islets of Langerhans:

see pancreaspancreas
, glandular organ that secretes digestive enzymes and hormones. In humans, the pancreas is a yellowish organ about 7 in. (17.8 cm) long and 1.5 in. (3.8 cm) wide. It lies beneath the stomach and is connected to the small intestine at the duodenum (see digestive system).
..... Click the link for more information.
.

Islets of Langerhans

 

the groups of cells in the pancreas of man and vertebrates (except cyclostomes) that form the endocrine part of the organ, secreting the hormones insulin and glucagon into the blood.

The islets of Langerhans are named for the German scientist P. Langerhans, who described them in 1869. In 1901, the Russian scientist L. V. Sobolev proved their endocrine function and established the occurrence of changes in the islets with diabetes mellitus. The dimensions of the islets of Langerhans are 50 to 500 microns, and there are between ten and 20 islets per mg of gland tissue. The islets do not communicate with the gland’s effluent ducts.

The islets of Langerhans develop from tubular processes of the anterior gut and, depending on the type of animal, consist of cells of several types. All animals have α cells and β cells. The granules of α cells are considered to be a form of glucagon deposit; the β cells, of insulin. C cells and D cells (the former have been found in the islets of Langerhans of guinea pigs; the latter, in man and dogs), which lack granules, are converted to α cells and β cells. In all, the tissue of the islets of Langerhans makes up 0.9 to 3.6 percent of the mass of the pancreas in children and 0.9 to 2.7 percent in adults.

V. M. SAMSONOVA

References in periodicals archive ?
Now, however, researchers have found a new way to study the insulin-producing beta-cells: by transferring the Islets of Langerhans to the eye.
2] and BPA in islets of Langerhans in vitro are initiated after they bind at the ncmER that is insensitive to the pure antiestrogen ICI (Nadal et al.
The encapsulation contains islets of Langerhans, with its main constituent the beta-cells, which provide the insulin production in the body.
A diagnostic test for glutamate toxicity in the islets of Langerhans is being developed by the authors, Dr.
Glucagon, secreted from pancreatic [alpha]-cells integrated within the islets of Langerhans, is involved in the regulation of glucose metabolism by enhancing the synthesis and mobilization of glucose in the liver.
The first grant will be used to conduct research to continue development of a hypothermic pancreas transporter for the safe and effective preservation of the pancreas for transplantation and Islets of Langerhans isolation.
The insulin-producing beta cells of the pancreas normally grow in clusters called islets of Langerhans.
The islets of Langerhans are structures in the pancreas that are responsible for regulating and producing insulin in response to changing glucose concentrations and are targets for autoimmune destruction or dysfunction in Type I Diabetes.
The two-year study, which will enroll eight participants at Uppsala University Hospital in Sweden, will evaluate the safety, survival and function of implanted human islets of Langerhans in the system.
They single out pancreatic cell clusters called the islets of Langerhans and destroy the tiny insulin factories within, called beta cells.
In vitro experiments with monocyte-derived stem cells (MDSC) have shown their capacity to differentiate into a wide variety of cell types including pancreatic beta cells which form into cell aggregates and generate into cluster-like structures that resemble pancreatic islets of langerhans.