Actions of the major digestive hormones secreted by enteroendocrine cells
|Anatomical terms of microanatomy|
Enteroendocrine cells are specialized cells of the gastrointestinal tract and pancreas with endocrine function. They produce gastrointestinal hormones or peptides in response to various stimuli and release them into the bloodstream for systemic effect, diffuse them as local messengers, or transmit them to the enteric nervous system to activate nervous responses. Enteroendocrine cells of the intestine are the most numerous endocrine cells of the body. They constitute an enteric endocrine system as a subset of the endocrine system just as the enteric nervous system is a subset of the nervous system. In a sense they are known to act as chemoreceptors, initiating digestive actions and detecting harmful substances and initiating protective responses. Enteroendocrine cells are located in the stomach, in the intestine and in the pancreas. Microbiota plays key roles in the intestinal immune and metabolic responses in these enteroendocrine cells via their fermentation product (short chain fatty acid), acetate.
Intestinal enteroendocrine cells
Intestinal enteroendocrine cells are not clustered together but spread as single cells throughout the intestinal tract.
Hormones secreted include somatostatin, motilin, cholecystokinin, neurotensin, vasoactive intestinal peptide, and enteroglucagon. The enteroendocrine cells sense the metabolites from intestinal commensal microbiota and, in turn, coordinate antibacterial, mechanical, and metabolic branches of the host intestinal innate immune response to the commensal microbiota.
K cells secrete gastric inhibitory peptide, an incretin, which also promotes triglyceride storage. K cells are mostly found in the duodenum.
L cells secrete glucagon-like peptide-1, an incretin, peptide YY3-36, oxyntomodulin and glucagon-like peptide-2. L cells are primarily found in the ileum and large intestine (colon), but some are also found in the duodenum and jejunum.
I cells secrete cholecystokinin (CCK), and are located in the duodenum and jejunum. They modulate bile secretion, exocrine pancreas secretion, and satiety.
Stomach enteroendocrine cells, which release gastrin, and stimulate gastric acid secretion.
Enterochromaffin cells are enteroendocrine and neuroendocrine cells with a close similarity to adrenomedullary chromaffin cells secreting serotonin.
Enterochromaffin-like cells or ECL cells are a type of neuroendocrine cell secreting histamine.
Located in the jejunum, N cells release neurotensin, and control smooth muscle contraction.
S cells secrete secretin from the duodenum and jejunum, and stimulate exocrine pancreatic secretion.
Also called Delta cells, D cells secrete somatostatin.
Mo cell (or M cell)
- found in crypts of the small intestine, especially in the duodenum and jejunum.
- Different from the Microfold cells (M cells) that are in Peyer's patches.
- Secrete motilin
Gastric enteroendocrine cells
Gastric enteroendocrine cells are found in the gastric glands, mostly at their base. The G cells secrete gastrin, post-ganglionic fibers of the vagus nerve can release gastrin-releasing peptide during parasympathetic stimulation to stimulate secretion. Enterochromaffin-like cells are enteroendocrine and neuroendocrine cells also known for their similarity to chromaffin cells secreting histamine, which stimulates G cells to secrete gastrin.
Other hormones produced include cholecystokinin, somatostatin, vasoactive intestinal peptide, substance P, alpha and gamma-endorphin.
Pancreatic enteroendocrine cells
Pancreatic enteroendocrine cells are located in the islets of Langerhans and produce most importantly the hormones insulin and glucagon. The autonomous nervous system strongly regulates their secretion, with parasympathetic stimulation stimulating insulin secretion and inhibiting glucagon secretion and sympathetic stimulation having opposite effect.
Other hormones produced include somatostatin, pancreatic polypeptide, amylin and ghrelin.
Rare and slow growing carcinoid and non-carcinoid tumors develop from these cells. When a tumor arises it has the capacity to secrete large volumes of hormones.
The very discovery of hormones occurred during studies of how the digestive system regulates its activities, as explained at Secretin § Discovery.
In rats (Rattus rattus) the short-chain fatty acid receptor GPR43 is expressed both by this cell type and by mast cells of the mucosa.
- APUD cells
- Neuroendocrine tumors
- List of human cell types derived from the germ layers
- ↑ "The new biology of gastrointestinal hormones". Physiological Reviews 78 (4): 1087–108. October 1998. doi:10.1152/physrev.19220.127.116.117. PMID 9790570. http://physrev.physiology.org/content/78/4/1087.full.
- ↑ 2.0 2.1 "The diffuse endocrine-paracrine system of the gut in health and disease: ultrastructural features". Scandinavian Journal of Gastroenterology. Supplement 70: 25–36. 1981. PMID 6118945.
- ↑ "The gut as the largest endocrine organ in the body". Annals of Oncology 12 Suppl 2 (suppl 2): S63–8. 2001. doi:10.1093/annonc/12.suppl_2.s63. PMID 11762354.
- ↑ "Minireview: Development and differentiation of gut endocrine cells". Endocrinology 145 (6): 2639–44. June 2004. doi:10.1210/en.2004-0051. PMID 15044355. http://endo.endojournals.org/content/145/6/2639.long.
- ↑ "Enteroendocrine cells: neglected players in gastrointestinal disorders?". Therapeutic Advances in Gastroenterology 1 (1): 51–60. July 2008. doi:10.1177/1756283X08093943. PMID 21180514.
- ↑ Principles and Methods of Toxicology (5th, revised ed.). CRC Press. 2007. p. 1547. ISBN 9781420005424. https://books.google.com/books?id=2IXMBQAAQBAJ&pg=PA1547.
- ↑ 7.0 7.1 "Enteroendocrine cells: a site of 'taste' in gastrointestinal chemosensing". Current Opinion in Endocrinology, Diabetes and Obesity 15 (1): 73–8. February 2008. doi:10.1097/MED.0b013e3282f43a73. PMID 18185066.
- ↑ "Taste receptors in the gastrointestinal tract. IV. Functional implications of bitter taste receptors in gastrointestinal chemosensing". American Journal of Physiology. Gastrointestinal and Liver Physiology 292 (2): G457–61. February 2007. doi:10.1152/ajpgi.00411.2006. PMID 17095755.
- ↑ "Microbiota-derived acetate activates intestinal innate immunity via the Tip60 histone acetyltransferase complex". Immunity 54 (8): 1683–1697.e3. August 2021. doi:10.1016/j.immuni.2021.05.017. ISSN 1074-7613. PMID 34107298.
- ↑ 10.0 10.1 "Quantitative distribution of enteroendocrine cells in the gastrointestinal tract of the adult opossum, Didelphis virginiana". Journal of Anatomy 140 (4): 591–605. June 1985. PMID 4077699.
- ↑ "Microbial Control of Intestinal Homeostasis via Enteroendocrine Cell Innate Immune Signaling". Trends Microbiol 28 (2): 141–149. February 2020. doi:10.1016/j.tim.2019.09.005. ISSN 0966-842X. PMID 31699645.
- ↑ "Nutrient-dependent secretion of glucose-dependent insulinotropic polypeptide from primary murine K cells". Diabetologia 52 (2): 289–298. February 2009. doi:10.1007/s00125-008-1202-x. PMID 19082577.
- ↑ Gutierrez-Aguilar, Ruth; Woods, Stephen C (February 2011). "Nutrition and L and K-enteroendocrine cells". Current Opinion in Endocrinology, Diabetes & Obesity 18 (1): 35–41. doi:10.1097/MED.0b013e32834190b5. PMID 21124210. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3884637/. Retrieved 24 January 2023.
- ↑ "The incretin system: glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors in type 2 diabetes". Lancet 368 (9548): 1696–705. November 2006. doi:10.1016/s0140-6736(06)69705-5. PMID 17098089. http://ww.novonordisk.com/images/diabetes/Liraglutide/Drucker-and-Nauck-Lancet-2006.pdf. Retrieved 2014-12-31.
- ↑ 15.0 15.1 "A beautiful cell (or two or three?)". Endocrinology 153 (7): 2945–8. July 2012. doi:10.1210/en.2012-1549. PMID 22730282.
- ↑ "Impaired gastric acid secretion in gastrin-deficient mice". The American Journal of Physiology 274 (3 Pt 1): G561–8. March 1998. doi:10.1152/ajpgi.1998.274.3.G561. PMID 9530158.
- ↑ "Action of serotonin on the gastrointestinal tract". Proceedings of the Society for Experimental Biology and Medicine 178 (3): 333–8. March 1985. doi:10.3181/00379727-178-42016. PMID 3919396.
- ↑ "Effects of neurotensin on isolated intestinal smooth muscles". European Journal of Pharmacology 50 (4): 349–57. August 1978. doi:10.1016/0014-2999(78)90140-1. PMID 699961.
- ↑ (in en) Neuropeptide Function in the Gastrointestinal Tract. CRC Press. 1990-12-11. ISBN 9780849361586. https://books.google.com/books?id=zZINAEddjA0C&q=mo+cell+motilin&pg=PA357.
- ↑ "Motilin Stimulates Gastric Acid Secretion in Coordination with Ghrelin in Suncus murinus". PLOS ONE 10 (6): e0131554. 2015-06-26. doi:10.1371/journal.pone.0131554. PMID 26115342. Bibcode: 2015PLoSO..1031554G.
- ↑ "[Endorphin-containing cells in the gastric antral mucosa in duodenal ulcer]". Biulleten' Eksperimental'noi Biologii I Meditsiny 96 (10): 32–4. October 1983. PMID 6194833.
- ↑ "Relationships between the autonomic nervous system and the pancreas including regulation of regeneration and apoptosis: recent developments". Pancreas 29 (2): e51–8. August 2004. doi:10.1097/00006676-200408000-00019. PMID 15257115.
- ↑ "Enteroendocrine tumors other than carcinoid: a review of clinically significant advances". Gastroenterology 128 (6): 1668–84. May 2005. doi:10.1053/j.gastro.2005.03.078. PMID 15887158.
- ↑ "Peripheral mechanisms in irritable bowel syndrome". N Engl J Med 367 (17): 1626–35. October 2012. doi:10.1056/NEJMra1207068. ISSN 0028-4793. PMID 23094724.
- Histology image: 11604loa – Histology Learning System at Boston University - "Endocrine System: duodenum, enteroendocrine cells"
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