Enteroendocrine cell#L cell

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.{{cite journal | vauthors = Krause WJ, Yamada J, Cutts JH | title = Quantitative distribution of enteroendocrine cells in the gastrointestinal tract of the adult opossum, Didelphis virginiana | journal = Journal of Anatomy | volume = 140 | issue = 4 | pages = 591–605 | date = June 1985 | pmid = 4077699 | pmc = 1165084 }} 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.{{cite journal | vauthors = Watnick PI, Jugder BE | title = Microbial Control of Intestinal Homeostasis via Enteroendocrine Cell Innate Immune Signaling | journal = Trends Microbiol | volume = 28 | issue = 2 | pages = 141–149 | date = February 2020 | pmid = 31699645 | pmc = 6980660 | doi = 10.1016/j.tim.2019.09.005 | issn = 0966-842X}}

K cells secrete gastric inhibitory peptide, an incretin, which also promotes triglyceride storage.{{cite journal | vauthors = Parker HE, Habib AM, Rogers GJ, Gribble FM, Reimann F | title = Nutrient-dependent secretion of glucose-dependent insulinotropic polypeptide from primary murine K cells | journal = Diabetologia | volume = 52 | issue = 2 | pages = 289–298 | date = February 2009 | pmid = 19082577 | pmc = 4308617 | doi = 10.1007/s00125-008-1202-x }} K cells are mostly found in the duodenum.{{cite journal |last1=Gutierrez-Aguilar |first1=Ruth |last2=Woods |first2=Stephen C |title=Nutrition and L and K-enteroendocrine cells |journal=Current Opinion in Endocrinology, Diabetes & Obesity |date=February 2011 |volume=18 |issue=1 |pages=35–41 |doi=10.1097/MED.0b013e32834190b5 |pmid=21124210 |pmc=3884637 }}

Also called neuropod cell.

L cells secrete glucagon-like peptide-1, an incretin, peptide YY_3-36, 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.{{cite journal | vauthors = Drucker DJ, Nauck MA | title = The incretin system: glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors in type 2 diabetes | journal = Lancet | volume = 368 | issue = 9548 | pages = 1696–705 | date = November 2006 | pmid = 17098089 | doi = 10.1016/s0140-6736(06)69705-5 | s2cid = 25748028 | url = http://ww.novonordisk.com/images/diabetes/Liraglutide/Drucker-and-Nauck-Lancet-2006.pdf | access-date = 2014-12-31 | archive-url = https://web.archive.org/web/20141231193325/http://ww.novonordisk.com/images/diabetes/Liraglutide/Drucker-and-Nauck-Lancet-2006.pdf | archive-date = 2014-12-31 | url-status = dead }}

I cells secrete cholecystokinin (CCK), and have the highest mucosal density in the duodenum with a decreasing amount throughout the small intestine.{{Cite journal |title=Expression of Cholecystokinin and its Receptors in the Intestinal Tract of Type 2 Diabetes Patients and Healthy Controls |url=https://academic.oup.com/jcem/article/106/8/2164/6283726 |access-date=2023-09-20 |journal=The Journal of Clinical Endocrinology & Metabolism |date=2021 |doi=10.1210/clinem/dgab367 |last1=Gilliam-Vigh |first1=Hannah |last2=Jorsal |first2=Tina |last3=Rehfeld |first3=Jens F. |last4=Pedersen |first4=Jens |last5=Poulsen |first5=Steen S. |last6=Vilsbøll |first6=Tina |last7=Knop |first7=Filip K. |volume=106 |issue=8 |pages=2164–2170 |pmid=34036343 |s2cid=235203208 |doi-access=free }} They modulate bile secretion, exocrine pancreas secretion, and satiety.{{cite journal | vauthors = Brubaker PL | title = A beautiful cell (or two or three?) | journal = Endocrinology | volume = 153 | issue = 7 | pages = 2945–8 | date = July 2012 | pmid = 22730282 | doi = 10.1210/en.2012-1549 | doi-access = free }}

{{Main|G cell}}

Stomach enteroendocrine cells, which release gastrin, and stimulate gastric acid secretion.{{cite journal | vauthors = Friis-Hansen L, Sundler F, Li Y, Gillespie PJ, Saunders TL, Greenson JK, Owyang C, Rehfeld JF, Samuelson LC | title = Impaired gastric acid secretion in gastrin-deficient mice | journal = The American Journal of Physiology | volume = 274 | issue = 3 Pt 1 | pages = G561–8 | date = March 1998 | doi = 10.1152/ajpgi.1998.274.3.G561 | pmid = 9530158 }}

Enterochromaffin cells are enteroendocrine and neuroendocrine cells with a close similarity to adrenomedullary chromaffin cells secreting serotonin.{{cite journal | vauthors = Ormsbee HS, Fondacaro JD | title = Action of serotonin on the gastrointestinal tract | journal = Proceedings of the Society for Experimental Biology and Medicine | volume = 178 | issue = 3 | pages = 333–8 | date = March 1985 | pmid = 3919396 | doi=10.3181/00379727-178-42016| s2cid = 34829257 }}

Enterochromaffin-like cells or ECL cells are a type of neuroendocrine cell secreting histamine.

===N cell===

Located in a increasing manner throughout the small intestine, with the highest levels found in the in ileum,{{Cite journal |title=Expression of Neurotensin and Its Receptors Along the Intestinal Tract in Type 2 Diabetes Patients and Healthy Controls | date=2023 |url=https://academic.oup.com/jcem/article/108/9/2211/7077196 |access-date=2023-09-20 |doi=10.1210/clinem/dgad146 | last1=Gilliam-Vigh | first1=Hannah | last2=Jorsal | first2=Tina | last3=Nielsen | first3=Sophie W. | last4=Forman | first4=Julie L. | last5=Pedersen | first5=Jens | last6=Poulsen | first6=Steen S. | last7=Vilsbøll | first7=Tina | last8=Knop | first8=Filip K. | journal=The Journal of Clinical Endocrinology & Metabolism | volume=108 | issue=9 | pages=2211–2216 | pmid=36916883 | s2cid=257506286 | url-access=subscription }} N cells release neurotensin, and control smooth muscle contraction.{{cite journal | vauthors = Kitabgi P, Freychet P | title = Effects of neurotensin on isolated intestinal smooth muscles | journal = European Journal of Pharmacology | volume = 50 | issue = 4 | pages = 349–57 | date = August 1978 | pmid = 699961 | doi = 10.1016/0014-2999(78)90140-1 }}

===S cell===

{{main|S cell}}

S cells secrete secretin mostly from the duodenum, but also in decreasing amounts throughout the rest of the small intestine,{{Cite journal |title=Expression of Secretin and its Receptor Along the Intestinal Tract in Type 2 Diabetes Patients and Healthy Controls | date=2023 |url=https://academic.oup.com/jcem/advance-article/doi/10.1210/clinem/dgad372/7202274 |access-date=2023-09-20 |doi=10.1210/clinem/dgad372 | last1=Gilliam-Vigh | first1=Hannah | last2=Jorsal | first2=Tina | last3=Nielsen | first3=Sophie W. | last4=Forman | first4=Julie L. | last5=Pedersen | first5=Jens | last6=Poulsen | first6=Steen S. | last7=Vilsbøll | first7=Tina | last8=Knop | first8=Filip K. | journal=The Journal of Clinical Endocrinology & Metabolism | pmid=37335970 | s2cid=259202375 | doi-access=free | url-access=subscription }} and stimulate exocrine pancreatic secretion.

{{main|Delta cell}}

Also called Delta cells, D cells secrete somatostatin.

• 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{{Cite book|url=https://books.google.com/books?id=zZINAEddjA0C&q=mo+cell+motilin&pg=PA357|title=Neuropeptide Function in the Gastrointestinal Tract|vauthors = Daniel EE|date=1990-12-11|publisher=CRC Press|isbn=9780849361586|language=en}}{{cite journal | vauthors = Goswami C, Shimada Y, Yoshimura M, Mondal A, Oda S, Tanaka T, Sakai T, Sakata I | title = Motilin Stimulates Gastric Acid Secretion in Coordination with Ghrelin in Suncus murinus | journal = PLOS ONE | volume = 10 | issue = 6 | pages = e0131554 | date = 2015-06-26 | pmid = 26115342 | pmc = 4482737 | doi = 10.1371/journal.pone.0131554 | bibcode = 2015PLoSO..1031554G | doi-access = free }}

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.{{cite journal | vauthors = Zverkov IV, Vinogradov VA, Smagin VG | title = [Endorphin-containing cells in the gastric antral mucosa in duodenal ulcer] | journal = Biulleten' Eksperimental'noi Biologii I Meditsiny | volume = 96 | issue = 10 | pages = 32–4 | date = October 1983 | pmid = 6194833 }}

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.{{cite journal | vauthors = Kiba T | title = Relationships between the autonomic nervous system and the pancreas including regulation of regeneration and apoptosis: recent developments | journal = Pancreas | volume = 29 | issue = 2 | pages = e51–8 | date = August 2004 | pmid = 15257115 | doi = 10.1097/00006676-200408000-00019 | s2cid = 15849806 }}

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.{{cite journal | vauthors = Warner RR | title = Enteroendocrine tumors other than carcinoid: a review of clinically significant advances | journal = Gastroenterology | volume = 128 | issue = 6 | pages = 1668–84 | date = May 2005 | pmid = 15887158 | doi = 10.1053/j.gastro.2005.03.078 | doi-access = free }}

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 Free fatty acid receptor 2 (GPR43) is expressed both by this cell type and by mast cells of the mucosa.{{cite journal | vauthors = Camilleri M | title = Peripheral mechanisms in irritable bowel syndrome | journal = N Engl J Med | volume = 367 | issue = 17 | pages = 1626–35 | date = October 2012 | pmid = 23094724 | doi = 10.1056/NEJMra1207068|issn = 0028-4793}}

• APUD cells
• Neuroendocrine tumors
• List of human cell types derived from the germ layers

{{Reflist}}

• {{BUHistology|11604loa}} - "Endocrine System: duodenum, enteroendocrine cells"

{{Gastrointestinal physiology}}

{{Endocrine system anatomy}}

{{Authority control}}

Category:Endocrine system

Category:Animal cells

Category:Stomach

Category:Secretory cells