Immunocytochemical localization of prolactin and growth hormone in the equine pituitary

• Published in: Journal of animal science Vol. 75; no. 11; pp. 3010 - 3018
• Main Authors: Rahmanian, M.S, Thompson, D.L. Jr, Melrose, P.A
• Format: Journal Article
• Language: English
• Published: Savoy, IL Am Soc Animal Sci 01.11.1997; American Society of Animal Science; Oxford University Press
• Subjects: Animals; Biological and medical sciences; CELL STRUCTURE; CELLS; CELLULE; CELULAS; CITOPLASMA; CYTOPLASM; CYTOPLASME; Cytoplasmic Granules - chemistry; Cytoplasmic Granules - metabolism; Cytoplasmic Granules - ultrastructure; ESTRUCTURA CELULAR; Female; Fundamental and applied biological sciences. Psychology; GLANDULA PITUITARIA; Growth Hormone - analysis; Growth Hormone - immunology; Growth Hormone - metabolism; HORMONAS; HORMONE; HORMONES; Horses; Horses - metabolism; HYPOPHYSE; Hypothalamus. Hypophysis. Epiphysis. Urophysis; Immune Sera - analysis; Immune Sera - immunology; IMMUNOCYTOCHEMISTRY; Immunohistochemistry - methods; IMMUNOLOGIE; IMMUNOLOGY; INMUNOLOGIA; JUMENT; LACTOTROPES; MAMMOSOMATOTROPES; MARES; Microscopes; MICROSCOPIA; MICROSCOPIE; MICROSCOPY; Microscopy, Electron - methods; Microscopy, Electron - veterinary; Morphology. Functional localizations; Ovary - cytology; Ovary - ultrastructure; PITUITARY GLAND; Pituitary Gland, Anterior - chemistry; Pituitary Gland, Anterior - cytology; Pituitary Gland, Anterior - metabolism; Progesterone - blood; PROLACTIN; Prolactin - analysis; Prolactin - immunology; Prolactin - metabolism; PROLACTINA; PROLACTINE; SECRECION; SECRETION; SECRETORY GRANULES; SOMATOTROPES; SOMATOTROPIN; SOMATOTROPINA; SOMATOTROPINE; STRUCTURE CELLULAIRE; TRANSMISSION ELECTRON MICROSCOPY; ULTRAESTRUCTURA; ULTRASTRUCTURE; Vertebrates: endocrinology; YEGUA; Vertebrata; Mammalia; Adenohypophyseal hormone; Immunocytochemistry; Prolactin; STH; Horse; Pituitary gland; Perissodactyla; Localization; Electron microscopy; Ungulata
• ISSN: 0021-8812; 1525-3163; 0021-8812
• DOI: 10.2527/1997.75113010x

The ultrastructural and immunoreactive staining characteristics of cells containing prolactin (lactotropes) and growth hormone (GH; somatotropes) in the anterior pituitaries of gonadally intact pony mares were studied at the electron microscopic level. Lactotropes included two morphological subsets: Type I cells were larger and contained large, dense, polymorphic granules that were scattered throughout the cytoplasm; Type II cells were smaller and contained small, dense, polymorphic granules that were predominantly found in peripheral areas of the cytoplasm. Lactotropes constituted 5 to 16% of the total number of cells in the pituitary. Somatotropes were medium-sized cells containing uniform, large, dense secretory granules. The somatotropes contained the largest secretory granules in the pituitary and represented 11 to 26% of the total number of cells. Type I lactotropes and somatotropes were readily distinguishable without immunocytochemical staining. Double-labeling of pituitary sections allowed for characterization of cells that contained both hormones (mammosomatotropes). These cells were morphologically indistinguishable from Type I lactotropes and constituted 6.5 to 16.5% of the total number of cells. Results from this study demonstrated that there are two cell populations that contain only prolactin (Type I and II lactotropes) and one cell population that contains only GH (somatotropes) in the equine pituitary, and an additional subset of cells that contains GH and prolactin in the same secretory granules