Catecholamine-Storing Vesicles: From Biosynthesis to Exo/Endocytosis

Abstract

Three types of catecholamine-storing vesicles have been characterized: (1) the chromaffin granules from adrenal medulla (2) the large dense core vesicles of sympathetic nerves and (3) the small dense core vesicles, which are also found in these nerves. The composition and molecular organization of chromaffin granules have been analyzed in great detail (see Winkler and Westhead 1980, Winkler and Carmichael 1982). The large dense core vesicles of sympathetic nerve closely resemble chromaffin granules in their biochemical composition and in their functional properties (Klein 1982). In addition it has become obvious that several features of these catecholamine-storing vesicles are of more general significance. As we will discuss below, the peptides present in the content of chromaffin granules, the chromagranins and neuropeptides, have a widespread distribution in endocrine and nervous tissues. Thus studies on their biosynthesis and their function have relevance not only for the adrenal medulla, but, e.g., also for large dense core vesicles in brain containing nonadrenergic transmitters.