SODIUM IONS AND SECRETION OF CATECHOLAMINES

1. Perfusion of bovine adrenal glands with a potassium‐free Tyrode solution results in an increased spontaneous release of catecholamines and an increased response to stimulation with carbamylcholine. 2. Perfusion with a Tyrode solution containing 70 m M‐KCl causes a marked secretion of catecholamines and a subsequent inhibition of secretion in response to stimulation with carbamylcholine. 3. Perfusion with sodium‐free media abolishes or severely reduces the secretory response of the gland to carbamylcholine and to 70 m M‐KCl although the basal secretion shows an initial rise. 4. Perfusion with sodium‐deficient media permits some retention of the secretory response. 5. A possible role for intracellular sodium ions in the secretion of catecholamines is discussed. © 1969 The Physiological Society