Studies on the adrenal cortex of hypophysectomized rats: A model for abnormal cellular atrophy and death

Summary Biochemical and ultrastructural studies indicate that the atrophy of adrenal cortex in hypoyhysectomized rats involves the following changes: (1) One to two days after hypophysectomy, there is loss of template activity resulting from cumulative DNA-damage and heterochromatinization.In vivo ACTH-administration led to recuperation of these cells, indicating damage during hypophysectomized state to be reversible. (2) If the duration of hypophysectomy is prolonged, some of the cells become irreversibly damaged and can no longer recuperate afterin vivo ACTH administration. (3) The period of most rapid cell death is from the third to seventh day after hypophysectomy. The cause of cell death is probably due to membrane damage in the absence of protein synthesis, leading to lysis of the cells. Lysozomes and macrophages are apparently not involved.Supported by U.S.P.H.S. grants AM-5384 and AM-13724 and taken in part from dissertations submitted by Chan and by Mostafapour to Wayne State University in partial fulfillment towards the Ph.D. degree.An invited article.