The fate of the chromaffin granule during catecholamine release from the adrenal medulla—I

Bovine adrenal glands were perfused in vitro or in situ with Locke's solution and were stimulated with acetylcholine (ACh). Catecholamine efflux rose sharply in response to acetylcholine but there was no change in the efflux of phospholipids or cholesterol, substances that are known to be present in the membranes of the chromaffin granules. The results support the view that the membranes of the chromaffin granules remain in the cell during catecholamine extrusion.