Glucagon and Other Hormones — A New Perspective

Abstract

DR. UNGER: We first became interested in the possibility that the alpha and beta cells and islets of Langerhans function, not as independent neighbors in the sense that some of the cells of the hypophysis function, but rather as a single, coordinated if not coupled functional unit designed to control the flux of key nutrients into and out of cells in accordance with supply and demand. This view was based on the remarkable qualitative relationship observed between the relative concentrations of the two hormones and the known, measured, or suspected need for a particular movement of nutrients. When the need of the organism was for breakdown of macro-molecules so that the important nutrients may be surrendered, the relative concentrations of insulin to glucagon was invariably low. Conversely, when synthesis of macromolecules was appropriate, the relative concentration of insulin to glucagon was always high. More recently there has been additional support for alpha-beta cell coupling. Dr. Orel has demonstrated an anatomical basis for intercellular communication between alpha and beta cells in the islets of Langerhans in the form of junctional complexes.