Somatropic cells (somatotropes) (from the Greek ''sōmat'' meaning "body" and ''tropikós'' meaning "of or pertaining to a turn or change") are cells in the

anterior pituitary The anterior pituitary (also called the adenohypophysis or pars anterior) is a major Organ (anatomy), organ of the endocrine system. The anterior pituitary is the glandular, Anatomical terms of location#Usage in human anatomy, anterior lobe that t ...

that produce

growth hormone Growth hormone (GH) or somatotropin, also known as human growth hormone (hGH or HGH) in its human form, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. It is thus important in ...

Structure

Somatotropic cells constitute about 30−40% of

cells. They release

(GH) in response to growth hormone releasing hormone (GHRH, or somatocrinin) or are inhibited by GHIH (somatostatin), both received from the

hypothalamus The hypothalamus (: hypothalami; ) is a small part of the vertebrate brain that contains a number of nucleus (neuroanatomy), nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrin ...

via the

hypophyseal portal system The hypophyseal portal system is a system of blood vessels in the microcirculation at the base of the brain, connecting the hypothalamus with the anterior pituitary. Its main function is to quickly transport and exchange hormones between the hyp ...

vein and the secondary plexus.

Clinical significance

Hormone deficiency

When levels of somatotropin are low in the body, a physician may prescribe human growth hormone as a drug. Deficiency in somatotrope secretion before puberty or before the end of new bone tissue growth, can lead to pituitary dwarfism. When growth hormone is deficient,

blood sugar The blood sugar level, blood sugar concentration, blood glucose level, or glycemia is the measure of glucose concentrated in the blood. The body tightly regulates blood glucose levels as a part of metabolic homeostasis. For a 70 kg (1 ...

is low because insulin is not opposed by normal amount of growth hormone.

Hormone excess

If there is an excess of growth hormone, it is usually because of over-secretion of somatotrope cells in the anterior pituitary gland. A significant amount of excess somatotrope secretion before puberty or before the end of new bone tissue growth can lead to

gigantism Gigantism (, ''gígas'', "wiktionary:giant, giant", plural γίγαντες, ''gígantes''), also known as giantism, is a condition characterized by excessive growth and height significantly above average height, average. In humans, this conditi ...

, a disease that causes excess growth of body (e.g. being over 7 ft. tall) and unusually long limbs. An excess of secretion of growth hormone after puberty can lead to

acromegaly Acromegaly is a disorder that results in excess growth of certain parts of the human body. It is caused by excess growth hormone (GH) after the growth plates have closed. The initial symptom is typically enlargement of the hands and feet. There ...

. This is a disease that causes abnormal growth in the hands, head, jaw, and tongue. Some symptoms associated with

include heavy sweating, oily skin, improper processing of sugars in the diet (

diabetes Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or the cells of th ...

high blood pressure Hypertension, also known as high blood pressure, is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms itself. It is, however, a major ri ...

, increased calcium in urine and swelling of the

thyroid gland The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans, it is a butterfly-shaped gland located in the neck below the Adam's apple. It consists of two connected lobes. The lower two thirds of the lobes are connected by ...

and

arthritis Arthritis is a general medical term used to describe a disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, Joint effusion, swelling, and decreased range of motion of ...

Other animals

Bovine somatotropin Livestock Dairy industry Bovine somatotropin or bovine somatotrophin (abbreviated bST and BST), or bovine growth hormone (BGH), is a peptide hormone produced by cows' pituitary glands. Like other hormones, it is produced in small quantities ...

occurs in the pituitary of cattle and differs in structure from human pituitary growth hormone and is biologically inactive in the human being. Bovine somatotropin aids in regulating the amount of milk produced. Recombinant bovine somatotropin (rBST) is a hormone that is injected in cows that increases milk production.

References