TETRAHYDROISOQUINOLINE ALKALOIDS: STIMULATED SECRETION FROM THE ADRENAL MEDULLA

¹ Clinical Research Center for Parkinson's and Allied Diseases, College of Physicians and Surgeons, Columbia University, New York, New York

Isolated cow adrenal glands were perfused for one hour with 23 mM acetaldehyde (1 mg/ml) in Tyrode's solution. This procedure resulted in synthesis within the glands of tetrahydroisoquinoline alkaloids, which are condensation products of acetaldehyde with endogenous epinephrine and norepinephrine. Subsequent stimulation of the glands by perfusion with carbachol or acetylcholine caused secretion of catecholamines and tetrahydroisoquinoline alkaloids. Depletion of calcium ions prevented these responses; secretory responses were restored by repletion of calcium ions. Pretreatment with tetracaine similarly blocked the secretion of catecholamines and tetrahydroisoquinoline alkaloids. The data indicate that tetrahydroisoquinoline alkaloids are secreted by a process similar to that controlling catecholamine release. The results of these model experiments support the concept that tetrahydroisoquinoline alkaloids may play a role as false transmitters after ingestion of alcoholic beverages.