INCORPORATION OF ³²P INTO PHOSPHOLIPIDS OF THE ADRENAL MEDULLA DURING AND AFTER STIMULATION BY SECRETOGOGUES

Abstract

It has been shown that there was a marked increase in the incorporation of ³²P into the phospholipid fraction when secretion of amines from the adrenal medulla (1, 2), enzyme from pancreas (3, 4) or the salivary gland (5, 6) and other substances from respective glands (7) were stimulated with cholinergic agents. From these striking phospholipid effects, it has been considered that phospholipids may play a role in the active secretion of proteins by exocrine glands and of amines by the adrenal medulla (7).
However, as to the time courses of acetylcholine-stimulated ³²P incorporation into phospholipids of the adrenal medulla, and of acetylcholine-evoked amine release, it was observed that amine release reached a maximum after 10 min; in contrast ³²P incorporation into phospholipids became apparent only after this interval of time (2). Furthermore, calcium ion had little influence on stimulating phospholipid effects of acetylcholine in the adrenal medulla (8) or pancreas slices (4), while their secretions in response to acetylcholine were completely inhibited by omission of calcium. Another possible role of the increased phospholipid metabolism might be involved in a post-process of chromafiin cells after the stimulated secretion.
The present work represents efforts to trace the role of phospholipid metabolism of the adrenal medulla in reference to the possible “recovery process” of the tissue after the stimulated secretion.