ABSTRACT
The anterior lobe (or adenohypophysis) is anatomically distinct from the hypothalamus (Box 7.2) and consists of a collection of endocrine cells. Originally three different cell-types were identified according to their ability to take up general histological stains; these were chromophobes, acidophils and basophils (Box 7.4). Newer immunohistochemical techniques allow classification of cells by their specific secretory products. About 50% of adenohypophyseal secretory cells are somatotrophs (synthesizing somatotrophin or GH), 10-25% lactotrophs (making prolactin), 15-20% corticotrophs (ACTH), 10-15% gonadotrophs (LH and FSH), and 3-5% thyrotrophs (TSH). Some cells, usually chromophobes, do not stain with any of the antibodies to the various anterior pituitary hormones although electron microscopy reveals that these cells contain secretory granules.
