SUBCELLULAR DISTRIBUTION AND RELEASE BY SYMPATHETIC NERVE STIMULATION OF DOPAMINE AND -METHYL DOPAMINE

¹ Laboratory of Clinical Science, National Institute of Mental Health, National Institutes of Health, United States Public Health Service, Bethesda, Maryland

Dopamine-H³ and a-methyl dopamine-H³ have both been shown to be retained by norepinephrine Storage particles and to be released by nerve stimulation. Previously, only -hydroxylated phenylethylamine derivatives were shown to be "false transmitters" capable of replacing norepinephrine in its storage sites. The present findings indicate that the -hydroxyl group is not essential for retention of sympathomimetic amines in the storage sites when a catechol group is present, and support the view that the sites from which adrenergic transmitters are released have binding properties similar to the norepinephrine storage granules.