Structural changes occurring in internal tissue of the duck (Anas platyrhynchos) following adenohypophysectomy and treatment in vivo and in vitro with corticotropin.

Adrenal glands from ACTH-treated intact ducks and chronically adenohypophysectomized ducks showed clear zonation into a subcapsular zone (SCZ) and an inner zone (IZ). Adenohypophysectomy caused ultrastructural changes in the IZ but not in the SCZ cells. These included increases in lipid droplets, changes in mitochondrial cristae from tubular to shelf-like, and changes in the shape of the nuclei from spherical to crenated. These changes were reversed by treatment with ACTH. Also, cells of the IZ, but not the SCZ, of adrenals from intact birds given ACTH showed more SER, more dense bodies, fewer lipid droplets and more prominent Golgi complexes. IZ cells incubated in buffer containing no ACTH developed mitochondria with shelf-like cristae and numerous opaque granules in the matrix. Exposure to buffer containing ACTH caused the mitochondrial cristae to become tubular and the matrix granules either decreased in number or disappeared. The granules could be extracted by incubating sections with chelating agents. The mitochondria in SCZ cells did not respond structurally to the presence of ACTH in the incubation medium but the matrix granules, like those in IZ cells, responded to the presence of chelating agents.