Association of adrenocorticotropic hormone activity with small secretory granules from rat anterior pituitary glands.

Abstract

Secretory granules were isolated from homogenates of rat anterior pituitary glands by differential centrifugation, nitration of the supernatant on Millipore filters and separation of the particulates by centrifuging the filtrate on a discontinuous density gradient. The granules from the basophils were recovered from the gradient in the form of a pellet and were shown to have maximum diameters of 140 and 200 m/u. Thyroid-stimulating hormone and the gonadotropins were associated, respectively, with these 2 populations of granules. Results with respect to adrenocorticotropic hormone now indicate that it is also associated with secretory granules in this pellet. (Endocrinology 78: 406, 1966) npHERE HAS been much controversy and M. speculation as to the pituitary cell type which produces adrenocorticotropic hormone (ACTH). Acidophils, basophils and Received August 23, 1965. This work was supported by Research Grant G9895 from the National Science Foundation. 1 Present address: Enzyme Institute, University of Wisconsin, Madison, Wisconsin. chromophobes have been supported at one time or another for this role. The current status of this problem is indicated by the work of Farquhar (1), Siperstein (2, 3) and Herlant (4). On the basis of electron microscope studies of rat pituitary glands, Farquhar (1) suggested that angular cells, designated as follicular cells, which surround a colloid-containing cavity are the likely sites of ACTH syn-