The islets of Langerhans have been the focus of research on the nature of diabetes mellitus ever since von Mering & Minkowski demonstrated in the 1890s that experimental diabetes can be induced in dogs by pancreatectomy. Following this pioneering work, the next major step was taken in 1922 by Banting & Best, who succeeded in isolating an active preparation of the blood-sugar lowering pancreatic secretion insulin, the body's most abundant peptide hormone and one of the most important in vital processes. In the past decade, advances in molecular techniques have made possible an understanding of the molecular level of the functioning of both the cells distributed at the centre of the islets, which produce insulin, and of the surrounding islet cells, which synthesize glucagon, somatostatin and pancreatic polypeptide. In consequence, new light has been thrown on both the etiology and the course of diabetes itself.

The aim of this book is to provide a contemporary and coherent view of the peptide hormones that are produced by the islets of Langerhans, as well as an explanation, at the molecular level, of defects in the organ that may lead to the pathological condition of insulin-dependent diabetes. The first section of the book is designed to provide a full account of recent information on islet hormone biosynthesis. The second section is devoted to an examination of the effects of deleterious conditions and agents on the functioning of islet cells, especially of the insulin-producing islet B-cells.