New hypothesis of insulin secretion.

Abstract

RELEASE of insulin from beta cells of the islets of Langer-hans occurs as a result of the movement of secretory granules to the surface of the cells. Here the membranous sacs encasing the granules fuse with the plasma membrane, rupture and liberate the granules into the extracellular space1. This process is called emiocytosis. Although glucose represents the most important physiologic stimulus for the release of insulin from the beta cells, it has been shown recently that the rates of secretion of insulin are also altered in the presence of a wide variety of other agents2. So far, little information is available concerning the relationship between the biochemical effects of these agents and the process of emiocytosis. We suggest here a working hypothesis for the events which occur between biochemical stimulation and the liberation of secretory granules into the extracellular space.