Isolation and characterization of chromaffin granules from a pheochromocytoma (PC 12) cell line

Chromaffin granules have been isolated from the pheochromocytoma clonal cell line, PC 12, The PC 12 cells, preloaded with radioactive catecholamines, were homogenized in isotonic sucrose and subjected to differential centrifugation and linear or stepwise sucrose gradient fractionation. Antigenic determinants characteristic of bovine chromaffin granules were detected both by immunofluorescence in intact cells and by complement fixation of isolated PC 12 granules. Electrophoretic analysis of the purified PC 12 granules revealed that the major proteins present have molecular weights similar to those of bovine chromaffin granule protein markers. The PC 12 catecholamine storage granules are thus suitable in vitro models for adrenal chromaffin granules.