STIMULATORY EFFECT OF ADENOSINE TRIPHOSPHATE AND MAGNESIUM ON THE RELEASE OF CATECHOLAMINES FROM ADRENAL MEDULLARY GRANULES

Abstract

It is well known that catecholamine is stored within specific granules in various tissues and when it is released from these granules it displays its physiological effects. Therefore, the mechanisms of storage and release of catecholamine have recently become a topic of interest. It was reported by Kirshner (1) and Carlsson et al. (2) that the uptake of ¹⁴C-catecholamine into the granules of the adrenal medulla was stimulated by ATP and Mg²⁺. Euler and Lishajko also showed ATP-Mg²⁺ dependent uptake of catecholarnine by the granules of adrenergic nerves (3, 4). The effect of ATP and Mg²⁺ on the uptake and release of catecholamine in the granules of adrenal medulla was also studied in this laboratory. It was found that on the addition of ATP and Mg²⁺, there was only slight or no inhibition of the release of catecholamine from the granules when they were incubated in sucrose solution, while when they were incubated in saline solution catecholamine release was greatly stimulated. This report gives further details of the stimulatory effect of ATP and Mg²⁺ on the release of catecholamine from the granules of adrenal medulla. A preliminary report of this work has been published (5, 6).