Somatotropes, also called somatotrophs, are cells located in the anterior pituitary. They synthesize and secrete somatotropin, or growth hormone. Somatotropes make up 40 to 50% of anterior pituitary cells. Somatoropes produce somatotropin (growth hormone) in response to somatocrinin (growth hormone releasing hormone); and the release of somatotropin is inhibited by somatostatin, both received from the hypothalamus via the hypophyseal portal system vein and the secondary plexus.
If there is an excess of growth hormone it is usually because of over-secretion of somatotrope cells in the anterior pituitary gland. This malfunction characterizes the disease gigantism. On the other hand, deficiency in somatotrope secretion before puberty, or before the end of new bone tissue growth, can lead to pituitary dwarfism.
Somatotropes are classified as acidophilic cells. These cells take years to grow and mature very slowly. If these cells grow large enough they can impair vision, cause headaches or damage other pituitary functions.