Structural changes in the nuclear body in the adrenal zona fasciculata of the calf following the administration of ACTH

The nuclear body was studied in parenchymatous cells of the adrenal zona glomerulosa and zona fasciculata of untreated calves of both sexes, of male calves which had been given only ACTH, and of male calves given ACTH and simultaneously subjected to sodium depletion by means of a unilateral parotid fistula. The nuclear body was observed to show structural and positional changes exclusively in the zona fasciculata, apparently in specific response to ACTH administration, leading to the development of a multilocular body. The latter body consisted in general of several single- or double-walled locules or large vesicles which often were collectively enclosed in a singular encompassing membrane. In the course of development the multilocular body was found to move from the vicinity of the nucleolus toward the nuclear membrane and in some instances to become contiguous with it. The nature and possible function of the nuclear body is discussed.