Category: Somatostatin
-
Enkephalins
An enkephalin is a pentapeptide involved in regulating nociception (pain sensation) in the body. The enkephalins are termed endogenous ligands, as they are internally derived and bind to the body’s opioid receptors. Discovered in 1975, two forms of enkephalin have been found, one containing leucine (“leu”), and the other containing methionine (“met”). Both are products of the proenkephalin gene. Endogenous opioid peptides There are three well-characterized families of opioid…
-
Enterochromaffin-like cells (ECL cells) are neuroendocrine and enteroendocrine cells that aid in the production of gastric acid via the release of histamine
Enterochromaffin-like cells or ECL cells are a type of neuroendocrine cell found in the gastric glands of the gastric mucosa beneath the epithelium, in particular in the vicinity of parietal cells, that aid in the production of gastric acid via the release of histamine. They are also considered a type of enteroendocrine cell. Function ECL cells synthesize and secrete histamine. These cells are stimulated by the hormones gastrin (not depicted in…
-
Delta cells (δ-cells or D cells) are somatostatin-producing cells
Delta cells (δ-cells or D cells) can be found in the stomach, intestine and the pancreatic islets. Delta cells comprise ca 5% of the cells in the islets but may interact with many more islet cells than suggested by their low numbers. In rodents, delta-cells are located in the periphery of the islets; in humans the islet architecture is generally less organized and…
-
Digestive enzymes
Digestive enzymes are a group of enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption into the cells of the body. Digestive enzymes are found in the digestive tracts of animals (including humans) and in the tracts of carnivorous plants, where they aid in the digestion of food, as well as inside cells,…
-
Arginine
Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. The molecule features a guanidino group appended to a standard amino acid framework. At physiological pH, the carboxylic acid is deprotonated (−CO2−) and both the amino and guanidino groups are protonated, resulting in a cation. Only the l-arginine (symbol Arg or R) enantiomer is found naturally. Arg residues are common components of proteins. It is encoded by the codons CGU, CGC,…
-
Somatostatin
Not to be confused with Somatocrinin or Somatomedin. Somatostatin, also known as growth hormone-inhibiting hormone (GHIH) or by several other names, is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G protein-coupled somatostatin receptors and inhibition of the release of numerous secondary hormones. Somatostatin inhibits insulin and glucagon secretion. “somatostatin”. Encyclopædia Britannica. Encyclopædia Britannica Online. Encyclopædia Britannica Inc., 2016. Web. 04 mag. 2016…
-
Oxytocin
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, Leng RI (November 2021). “Oxytocin: A…
-
Cholecystokinin aka pancreozymin notes
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, Rex A, Voits M, Voigt…
-
Gastrin
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 apical membrane of parietal cells (which…