Lysosomal accumulation of neuromelanin-like material in astrocytes after exposure to norepinephrine.

The objective of this work was to characterize the granules seen accumulating within the cytoplasm of astrocytes upon chronic treatment of astrocytic cultures with norepinephrine as well as other catecholamines. The ultrastructure of the granules, as well as their ability to stain strongly with Schmorl's ferric-ferricyanide, suggested that the granules consisted of lipofuscin or neuromelanin. The silver staining property of the granules indicated that they consisted of neuromelanin. Astrocytic cultures may make good models in examining the possible roles of neuromelanin in living cells.