Biological Chemistry - Berezov T. T., Korovkin B. F. 1998

Hormones
Pituitary Hormones
Somatotropic hormone (STH, growth hormone, somatotropin)

Growth Hormone was discovered in anterior pituitary extracts as early as 1921, though it was not isolated in a chemically pure form until 1956–1957. STH is synthesized in the acidophilic Cells of the anterior pituitary; its concentration in the Pituitary Gland is 5–15 mg per 1 g of tissue, which is 1,000 times higher than the concentration of other Pituitary Hormones. To date, the Introduction/19.html">Primary Structure of the protein molecule of human, bovine, and ovine STH has been fully elucidated. Human STH consists of 191 Amino Acids and contains two Disulfide Bonds; the N- and C-terminal Amino acids are represented by phenylalanine.

STH exhibits a wide spectrum of biological activities. It affects all cells of the body, regulating the intensity of carbohydrate, protein, lipid, and Mineral METABOLISM. It enhances The Biosynthesis of protein, DNA, RNA, and Glycogen, while simultaneously promoting fat mobilization from storage depots and the Breakdown of Higher Fatty acids and glucose in Tissues. In addition to activating anabolic processes—accompanied by an increase in body size and skeletal growth—STH coordinates and regulates The rate of metabolic processes. Furthermore, STH in humans and primates (but not in other animals) possesses measurable lactogenic activity. It is hypothesized that many of the BIOLOGICAL EFFECTS OF this hormone are mediated through a specific protein factor produced in the Liver under the Influence of the hormone. This factor was initially called the sulfating or thymidic factor because it stimulates the incorporation of sulfate into Cartilage, thymidine into DNA, uridine into RNA, and Proline into Collagen. By nature, this factor turned out to be a peptide with a Molecular Weight of 8,000. Given its biological role, it was named "somatomedins"—meaning a mediator of STH action in the Organism.

STH regulates the GROWTH AND DEVELOPMENT of the entire organism, as confirmed by clinical observations. For instance, in Pituitary dwarfism (a condition known in the literature as panhypopituitarism, associated with congenital underdevelopment of the pituitary gland), proportional underdevelopment of the entire body, including the Skeleton, is observed, although no significant deviations in mental development are noted. In adults, a series of disorders associated with pituitary hypofunction or hyperfunction also develop. A well-known condition is acromegaly (from the Greek akros — extremity, megas — large), characterized by disproportionately intense growth of certain body parts—such as hands, feet, chin, supraorbital ridges, Nose, Tongue—and enlargement of Internal Organs. The disease is presumably caused by a tumor lesion in the anterior pituitary gland.