HISTOLOGICAL EVIDENCE FOR A NEURAL ROLE IN THE DEPLETION OF ADRENAL CATECHOLAMINES BY DESERPIDINE AND TM-10

¹ Department of Physiology, University of Illinois College of Medicine and Department of Physiology and Pharmacology, Chicago Medical School, Chicago, Illinois
² Department of Physiology and Pharmacology, The Chicago Medical School, Chicago, Illinois

Histologic study of the depletion of the catecholamines of the adrenal medulla of the rat by deserpidine or TM-10 shows: a) The chromaffin cells are grouped into islets, each containing from 8 to 20 cells in cross-section, which seem to act as functional units. b) There are clearly identifiable norepinephrine islets in 20 to 30% of the cross-sectional area of a given section, and these seem to be separately regulated as compared to the remaining epinephrine islets. c) All the islets are depleted and repleted in a step-wise manner, and adjacent islets seem to be regulated independently of one another. d) The histologic depletion by deserpidine is blocked if the splanchnic nerves are previously sectioned, suggesting that there is a neural regulation and that perhaps each islet may be presumed to act as a ‘motor unit.’ e) The histologic restitution of the catecholamines is also islet bound; however, the restoration is independent ent of the neural regulation. f) TM-10 (massive doses) has histologic effects that are less complete, but qualitatively similar to deserpidine; however, tranquilization is absent.

Deserpidine causes a "stress" response in the adrenal gland as judged by the ascorbic acid concentration. However, the response is not prevented by previous splanchnicotomy. Hypophysectomy prevents the above "stress" response, but not the catecholamine depletion following deserpidine.