Pituitary Function and Neoplasia

The cell types of the mature adenohypophysis are derived embryologically from somatic ectoderm associated with Rathke’ s pouch. Highly specific trophic factors determine a precise temporal and spatial development of cells expressing unique gene products. The six hormones of the anterior pituitary gland are expressed by at least five distinct hormone-producing cell populations, including corticotrophs (pro-opiomelanocortin, POMC), somatotrophs (growth hormone, GH), lactotrophs (prolactin, PRL), thyrotrophs (thyroid-stimulating hormone, TSH), and gonadotrophs (follicle-stimulating hormone, FSH, and luteinizing hormone, LH) (Table 48-1). Each of these cells are identified by specific assays of polypeptide gene expression, including single-cell mRNA, immunoelectron microscopy, and immunocytochemical assays. The temporal ontogeny of these gene products is initially adrenocorticotropic hormone (ACTH) and α-subunit. After the appearance of Pit-1, apou-domain transcription factor, mixed mammosomatroph products appear. Distinct GH- and PRL-expressing cells PRL-expressing cells follow and TSH, LH, and FSH are the final IPII types to mature at 12 weeks. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.