ANTERIOR PITUITARY-LIKE HORMONES

Chorionic Somatomammotropin. Three genes encode human chorionic somatomammotropin [11085-36-2] (hCS). These are located within a cluster of genes on human chromosome 17 which code for pituitary growth hormone [12629-01 -5] (GH-N), placental GH [109675-94-7J (GH-V), and three hCS molecules, ie, hCS-A, hCS-B, and hCS-V (1 3), also referred to as human placental lactogens. All of these molecules ate closely related to GH in stmcture (Fig. 1). Placental lactogens also exist in rodents and mminants however, these hormones are more closely related to prolactin than GH. 

GS = choriosomatomammotropin = same amino acid as GH-N. Disulfide bonds cormect Cys molecules at positions 53—165 and 182—189. Asn-140 of 

Kirk-Othmer Encyclopedia of Chemical Technology (4th Edition) 

Antibodies have been generated which produce immunoassays that discriminate between GH-V and GH-N. These assay systems have shown that the secretion of GH-V becomes elevated at about three weeks of pregnancy and increases to approximately 15 ng/mL near term (8). The physiological role of GH-V is uncertain. Genetic deficiency of GH-V does not adversely affect pregnancy or fetal development (9). GH-V is a potent growth-stimulator but possesses considerably less lactogenic activity than GH-N (10). There are no clinical appHcations (ca 1993) for GH-V. 

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Anterior pituitary hormones, Anterior pituitary-like hormones. Posterior pituitary hormones. Human growth hormone. 

Matteri RL (1995) Hormones (anterior pituitary-like hormones). Kirk-Othmer Encyclopedia of Chemical Technology, 4th edn, Vol 13. Wiley, New York, pp 381-391. 

Like many other neuropeptides, NT serves a dual function as a neurotransmitter or neuromodulator in the central nervous system and as a local hormone in the periphery. When administered centrally, NT exerts potent effects including hypothermia, antinociception, and modulation of dopamine neurotransmission. When administered into the peripheral circulation, it causes vasodilation, hypotension, increased vascular permeability, increased secretion of several anterior pituitary hormones, hyperglycemia, inhibition of gastric acid and pepsin secretion, and inhibition of gastric motility. It also exerts effects on the immune system. 

Growth hormone is a peptide hormone produced by the anterior pituitary. It produces growth at open epiphyses via stimulation of insulin-like growth factor I (IGF-I, somatomedin C). It also causes lipolysis in adipose tissue and growth of skeletal muscle. 

The anterior pituitary releases GH in 6 to 8 pulsatile bursts over a 24 h period the major portion is released just prior to deep sleep. Its secretion is controlled by hypothalamic peptides GH-releasing hormone stimulates GH secretion, while somatostatin inhibits it. GH stimulates the synthesis of insulin-like growth factor-1 (IGF-1 somatomedin C) mainly, but not solely, in the liver. GH and IGF-1 receptors are widely scattered throughout the body, and both hormones exert important metabolic actions in various tissues, especially muscle and bone. 

Adrenocorticotropic hormone derives from the anterior pituitary in response to the leptin-or stress-induced anorexigenic, hypothalamic CRH. Corticotropin (like enkephalins and MSHs) derives from a precursor polypeptide pro-opiomelanocortin. Corticotropin induces the catabolic adrenal cortex corticosteroid cortisol and the mineralocorticoid aldosterone (Chapter 11) and is an important regulator of immune responses including chemotaxis and phagocytosis. Corticotropin acts via GPCRs to activate Gas and increase cAMP in anterior pituitary cells. 

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