Calcitonin is a 32 amino acid peptide hormone secreted by PARAFOLLICULAR CELLS (also known as C cells) of the thyroid (or endostyle) in humans and other chordates in the ultimopharyngeal body. It acts to reduce blood calcium (Ca2+), opposing the effects of PARATHYROID HORMONE (PTH). Its importance in humans has not been as well established as its importance in other animals, as its function isContinue Reading
Corticotropin-like intermediate [lobe] peptide (CLIP), also known as adrenocorticotropic hormone fragment 18-39 (ACTH(18-39)), is a naturally occurring, endogenous neuropeptide with a docosapeptide structure and the amino acid sequence Arg-Pro-Val-Lys-Val-Tyr-Pro-Asn-Gly-Ala-Glu-Asp-Glu-Ser-Ala-Glu-Ala-Phe-Pro-Leu-Glu-Phe. CLIP is generated as a proteolyic cleavage product of adrenocorticotropic hormone (ACTH), Gianoulakis C, Seidah NG, Routhier R, Chrétien M (December 1979). “Biosynthesis and characterization of adrenocorticotropic hormone, alpha-melanocyte-stimulating hormone, and an NH2-terminal fragment of the adrenocorticotropic hormone/beta-lipotropinContinue Reading
Melanin-concentrating hormone (MCH), also known as pro-melanin stimulating hormone (PMCH), is a cyclic 19-amino acid orexigenic hypothalamicpeptide originally isolated from the pituitary gland of teleost fish, where it controls skin pigmentation. Barson JR, Morganstern I, Leibowitz SF (2013). “Complementary roles of orexin and melanin-concentrating hormone in feeding behavior”. International Journal of Endocrinology. 2013: 983964. doi:10.1155/2013/983964. PMC 3727095. PMID 23935621. In mammals it is involved in theContinue Reading
Pro-opiomelanocortin (POMC) is a precursor polypeptide with 241 amino acid residues. POMC is synthesized in corticotrophs of the anterior pituitary from the 267-amino-acid-long polypeptide precursor pre-pro-opiomelanocortin (pre-POMC), by the removal of a 26-amino-acid-long signal peptide sequence during translation. “pro-opiomelanocortin preproprotein [Homo sapiens] – Protein – NCBI”. www.ncbi.nlm.nih.gov. Retrieved 30 December 2020. POMC is part of the central melanocortin system. Function POMC is cut (cleaved) to give rise to multiple peptide hormones. EachContinue Reading
Oxytocin (Oxt or OT) is a peptide hormone and neuropeptide normally produced in the hypothalamus and released by the posterior pituitary. Gray’s Anatomy: The Anatomical Basis of Clinical Practice (41 ed.). Elsevier Health Sciences. 2015. p. 358. ISBN 978-0-7020-6851-5. It plays a role in social bonding, reproduction, childbirth, and the period after childbirth. Audunsdottir K, Quintana DS (2022-01-25). “Oxytocin’s dynamic role across the lifespan”. Aging Brain: 100028. doi:10.1016/j.nbas.2021.100028. ISSN 2589-9589. S2CID 246314607. Leng G, LengContinue Reading
History Structure Function Gastrointestinal Digestion Satiety The effects of CCK vary between individuals. For example, in rats , CCK administration significantly reduces hunger in adult males, but is slightly less effective in younger subjects, and even slightly less effective in females. The hunger-suppressive effects of CCK also are reduced in obese rats. Fink H,Continue Reading
History and name Gene, transcription products, and structure Ghrelin cells Alternative names Location Features Function and mechanism of action Blood levels Ghrelin receptor Locations of action Glucose metabolism Sleep Reproductive system Fetus and neonate Anorexia and obesity Disease management Gastric bypass surgery See also External links Look up ghrelin in Wiktionary, theContinue Reading
Prolactin Agonists An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist. Etymology: From the Greek αγωνιστής (agōnistēs), contestant; champion; rivalContinue Reading
In mammals, prolactin is associated with milk production; in fish it is thought to be related to the control of water and salt balance. Prolactin also acts in a cytokine-like manner and as an important regulator of the immune system. It has important cell cycle-related functions as a growth-, differentiating- andContinue Reading
Gastrin-releasing peptide, also known as GRP, is a neuropeptide, a regulatory molecule that has been implicated in a number of physiological and pathophysiological processes. Most notably, GRP stimulates the release of gastrin from the G cells of the stomach. Function GRP is also involved in the biology of the circadian system, playing a role in the signaling of light toContinue Reading
Progastrin is an 80-amino acid intracellular protein and the precursor of gastrin, a gastrointestinal hormone produced by G cells in the gastric antrum. Fiona M., Gribble; Frank, Reimann; Geoffrey, P. Roberts (2018). Gastrointestinal Hormones. Physiology of the Gastrointestinal Tract, Elsevier. pp. 31–70. The main function of gastrin is to regulate acid secretion. Rehfeld, Jens F.; Goetze, Jens Peter (2005). “2 The Post-Translational PhaseContinue Reading
Gastrin is a peptide hormone that stimulates secretion of gastric acid (HCl) by the parietal cells of the stomach and aids in gastric motility. It is released by G cells in the pyloric antrum of the stomach, duodenum, and the pancreas. Gastrin binds to cholecystokinin B receptors to stimulate the release of histamines in enterochromaffin-like cells, and it induces the insertion of K+/H+ ATPase pumps into the apicalContinue Reading
