The following hormones are secreted by the islets of Langerhans: amylin, insulin, glucagon, somatostatin and pancreatic polypeptide. The islets are the cells that make up the endocrine pancreas. Other pancreatic juices are produced by the pancreas, but these aid in digestion and are not produced in the islets of Langerhans.
The endocrine pancreas secretes hormones that are vital in maintaining healthy blood-sugar levels. Type 1 diabetes occurs when an autoimmune process destroys the beta cells of the islets of Langerhans, and the body is no longer able to produce insulin. Lifelong injections of pharmaceutical insulin or transplantation of donor islet cells can correct Type 1 diabetes.