The Chromaffin Granule and Possible Mechanisms of Exocytosis

This chapter discusses the chromaffin granule and possible mechanisms of exocytosis. Chromaffin granules and chromaffin cells have been subjects of biological and chemical investigation for over a quarter of a century, and fundamental, seminal information has been obtained about the general process of secretion from cells. Chromaffin granules play several roles in adrenal medullary cells, some of which may be amenable to biochemical analysis. This view presumes that chromaffin granules are assembled in the Golgi apparatus, by analogy to studies on other cells such as those of the pancreas, though in fact studies on the ultrastructural biochemistry of chromaffin-granule assembly are in a relatively primitive stateThis chapter describes current information on the biochemical basis of exocytosis as viewed from the vantage point of the chromaffin granule. It presents a general view of exocytosis and included granule assembly, the mechanism of calcium action, the release event, and recovery of the granule membrane after secretion.