The corticotroph of the rat adenohypophysis: A comparative study

Abstract

The immunological and cytological specificity of antiserum to adrenocorticotrophic hormone was established and the corticotroph defined at the light microscopic level by immunocytochemistry. Our observations substantiated recent reports by several investigators. By comparing thin methacrylate sections with adjacent 1 p-methacrylate sections immunochemically stained with anti-ACTH, the ACTH cell was identified at the ultrastructural level and its morphology studied. Using the criteria established at light and electron microscopic levels, the corticotroph was readily found in tissue which had been fixed in paraformaldehyde-osmium mixture and embedded in epoxy resin. Ultrastructural changes in this cell in response to experimentally designed alterations in t h e pituitary ACTH levels confirmed this identification. The ACT11 cell was likewise identified in glutaraldehyde-fixed material. Thyrotrophs were tentatively defined. Several ultrastructural studies responsible for conflicting reports in the literature were investigated. It was concluded that the corticotroph is a unique cell type and that granule size and morphology remain important criteria for adenohypophyseal cell identification regardless of the fixation used. The need for a definitive immunocytochemical study of thyrotrophs at the ultrastructural level was recognized.

Identification of Acth Cells and TSH Cells in Rat Anterior Pituitary With the Unlabeled Antibody Enzyme Method on Adjacent Thin and Thick Sections

“…Baker (2) reported that some ACTH cells could be stained with AF and PAS reaction at the light microscopic level. Bowie et al (6) also reported that the secretory granules of the ACTH cell are responsible for the positive PAS reaction of the methacrylate sections for electron microscopy. Such an inconstant reaction to the PAS technique may be responsible for the physiological condition of ACTH cell.…”

“…To date, however, methodologic difficulties have prevented application of this technique to distinguish between the ACTH and TSH cell types at electron microscopic resolution (6,17,18,24,26 Two groups of adult male rats of the Wistar strain were used. The control group consisted of untreated rats, and the other group consisted of rats sacrificed at 1, 3, 5 and 7 days after adrenalectomy.…”

Immunoelectron-Microscopic and Morphometric Study of the Rat Corticotrophs after Adrenalectomy

“…There have been several studies concerning the ultra structure of the corticotrophs of rat anterior pituitary both in normal and adrenalectomized animals [1][2][3][4][5]. Among them, Nakayama et al |1] and Kurosumi et al [5] pre sented quantitative data that the secretory granules of the corticotrophs decreased in number and that the ratio of immature/mature granules increased after adrenalec tomy.…”

Various types of the pituitary folliculo-stellate cells involving the Siperstein's corticotroph in the normal rats.

“…Immunohistochemical evidence sustains the genuine ACTH secretion from the Siperstein's cells (Moriarty and Halmi, 1972;Bowie et al, 1973;Moriarty et al, 1975). We intend to present an innovation on the differentiation of F-S cells in the gland, and the present electron microscopy (teals with the substantial existence of various types of F-S cells involving a corticotroph.…”