Pancreatic islets by scarce alpha, delta and PP cells in the periphery, human islets display alpha and beta cells in close relationship with each other throughout the cluster. Islets can influence each other through paracrine and autocrine communication, and beta cells are coupled electrically to six to seven other beta cells (but not to other cell types). The paracrine feedback system of the pancreatic islets has the following structure: A large number of G protein-coupled receptors (GPCRs) regulate the secretion of insulin, glucagon and somatostatin from pancreatic islets, and some of these GPCRs are the targets of drugs used to treat type-2
Paul Langerhans Paul Langerhans Paul Langerhans (25 July 1847 – 20 July 1888) was a German pathologist, physiologist and biologist, credited with the discovery of the cells that secrete insulin, named after him as the islets of Langerhans. Langerhans was born in Berlin on 25 July 1847, the son of a physician. He later entered the renowned Graues Kloster in the same city. Due to his outstanding performance he was exempted from the final oral examinations. He began his medical studies at the University of Jena and completed them in Berlin. In February 1869, he presented a thesis entitled “Contributions to the