Molecular Mechanisms of Storage of Transmitters in Synaptic Terminals

MUCH more is known about the molecular constitution of the storage mechanism for catecholamines than about how acetylcholine (ACh) is stored, although morphine and related drugs are known to inhibit its release. Because adenosine triphosphate (ATP) seems to be involved in the storage of catecholamines in the chromaffin granules of the adrenal medulla we looked for a special affinity between morphine and various phosphorylated nucleosides which might be concerned in the storage of ACh. Acetylcholine itself could not be tested by these techniques because it lacks native fluorescence.