n.
A polypeptide hormone produced chiefly by the hypothalamus that inhibits the secretion of various other hormones, such as somatotropin, glucagon, insulin, thyrotropin, and gastrin.
[SOMATO(TROPIN) + -STAT + -IN.]
somatostatin
Dictionary:
so·mat·o·stat·in (sō-măt'ə-stăt'n, sō'mə-tə-) 
|
n.
A polypeptide hormone produced chiefly by the hypothalamus that inhibits the secretion of various other hormones, such as somatotropin, glucagon, insulin, thyrotropin, and gastrin.
Related Videos:
somatostatin |
Sci-Tech Encyclopedia:
Somatostatin |
A naturally occurring regulatory peptide that carries out numerous functions in the human body, including the inhibition of growth hormone secretion from the anterior pituitary gland. Somatostatin consists of 14 amino acids; two cysteine residues are joined by a disulfide bond so that the peptide forms a ring structure. A larger variant of this peptide, called somatostatin-28, is produced in some cells and has an additional 14 amino acids attached at the amino-terminal end of normal somatostatin (somatostatin-14).
Somatostatin acts primarily as a negative regulator of a variety of different cell types, blocking processes such as cell secretion, cell growth, and smooth muscle contraction. It is secreted from the hypothalamus into the portal circulation and travels to the anterior pituitary gland, where it inhibits the production and release of both growth hormone and thyroid-stimulating hormone. Many tissues other than the hypothalamus contain somatostatin, suggesting that this peptide has numerous roles.
Each of the functions of somatostatin is initiated by the binding of the peptide to one or more of five different cell-surface receptor proteins, thereby activating one or more intracellular G-proteins and initiating biochemical signaling pathways within the cell. See also Signal transduction.
Analogs of somatostatin have been synthesized that are smaller, more potent, longer-lasting, and more specific in their biological effects than natural somatostatin. Some of these analogs have become useful as drugs. See also Endocrine system (vertebrate); Hormone; Neurosecretion; Pituitary gland.
Sports Science and Medicine:
somatostatin |
A peptide secreted in the retina, the hypothalamus, and some other areas of the brain where it may function as a neurotransmitter. Somatostatin is also secreted by the pancreas. It inhibits the release of human growth hormone.
Veterinary Dictionary:
somatostatin |
A cyclic tetradecapeptide hormone and neurotransmitter that inhibits the release of peptide hormones in many tissues. It is released by the hypothalamus to inhibit the release of growth hormone (GH, somatotropin) and thyroid-stimulating hormone (TSH) from the anterior pituitary; it is also released by the delta cells of the islets of Langerhans in the pancreas to inhibit the release of glucagon and insulin and by the similar D cells in the gastrointestinal tract.
Wikipedia:
Somatostatin |
| edit |
| Somatostatin | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
 |
|||||||||||
| Identifiers | |||||||||||
| Symbols | SST; SMST | ||||||||||
| External IDs | OMIM: 182450 MGI: 98326 HomoloGene: 819 GeneCards: SST Gene | ||||||||||
|
|||||||||||
| RNA expression pattern | |||||||||||
 |
|||||||||||
| More reference expression data | |||||||||||
| Orthologs | |||||||||||
| Species | Human | Mouse | |||||||||
| Entrez | 6750 | 20604 | |||||||||
| Ensembl | ENSG00000157005 | ENSMUSG00000004366 | |||||||||
| UniProt | P61278 | Q545V6 | |||||||||
| RefSeq (mRNA) | NM_001048 | NM_009215 | |||||||||
| RefSeq (protein) | NP_001039 | NP_033241 | |||||||||
| Location (UCSC) | Chr 3: 188.87 - 188.87 Mb |
Chr 16: 23.8 - 23.81 Mb |
|||||||||
| PubMed search | [1] | [2] | |||||||||
Somatostatin (also known as growth hormone-inhibiting hormone (GHIH) or somatotropin release-inhibiting factor (SRIF)) 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 has two active forms produced by alternative cleavage of a single preproprotein: one of 14 amino acids, the other of 28 amino acids.[1]
|
Contents
|
Production
Digestive system
Somatostatin is secreted in several locations in the digestive system:
- stomach
- intestine
- delta cells of the pancreas[2]
Brain
Somatostatin is produced by neuroendocrine neurons of the periventricular nucleus of the hypothalamus. These neurons project to the median eminence, where somatostatin is released from neurosecretory nerve endings into the hypothalamo-hypophysial portal circulation. These blood vessels carry somatostatin to the anterior pituitary gland, where somatostatin inhibits the secretion of growth hormone from somatotrope cells. The somatostatin neurons in the periventricular nucleus mediate negative feedback effects of growth hormone on its own release; the somatostatin neurons respond to high circulating concentrations of growth hormone and somatomedins by increasing the release of somatostatin, so reducing the rate of secretion of growth hormone.
Somatostatin is also produced by several other populations that project centrally, i.e., to other areas of the brain, and somatostatin receptors are expressed at many different sites in the brain. In particular, there are populations of somatostatin neurons in the arcuate nucleus, the hippocampus, and the brainstem nucleus of the solitary tract.
Actions
Somatostatin is classified as an inhibitory hormone,[1] whose actions are spread to different parts of the body:
Anterior pituitary
In the anterior pituitary gland, the effects of somatostatin are:
- Inhibit the release of growth hormone (GH)[3] (thus opposing the effects of Growth Hormone-Releasing Hormone (GHRH))
- Inhibit the release of thyroid-stimulating hormone (TSH)
Gastrointestinal system
 |
This article is in a list format that may be better presented using prose. You can help by converting this article to prose, if appropriate. Editing help is available. (March 2009) |
- Somatostatin suppresses the release of gastrointestinal hormones
- Lowers the rate of gastric emptying, and reduces smooth muscle contractions and blood flow within the intestine[3]
- Suppresses the release of pancreatic hormones
- Suppresses the exocrine secretory action of pancreas.
Synthetic substitutes
 |
This sect does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (March 2009) |
Octreotide (brand name Sandostatin, Novartis Pharmaceuticals) is an octapeptide that mimics natural somatostatin pharmacologically, though is a more potent inhibitor of growth hormone, glucagon, and insulin than the natural hormone and has a much longer half-life (approximately 90 minutes, compared to 2-3 minutes for somatostatin). Since it is absorbed poorly from the gut, it is administered parenterally (subcutaneously, intramuscularly, or intravenously). It is indicated for symptomatic treatment of carcinoid syndrome, acute variceal bleeding, and acromegaly. It is also finding increased use in polycystic diseases of Liver and Kidney.
Lanreotide (INN) is a medication used in the management of acromegaly and symptoms caused by neuroendocrine tumors, most notably carcinoid syndrome. It is a long-acting analogue of somatostatin, like octreotide.
Lanreotide(as lanreotide acetate) is manufactured by Ipsen, and marketed under the trade name Somatuline. It is available in several countries, including the United Kingdom, Australia, and Canada, and was approved for sale in the United States by the Food and Drug Administration (FDA) on August 30, 2007.
References
- ^ a b Costoff A. "Sect. 5, Ch. 4: Structure, Synthesis, and Secretion of Somatostatin". Endocrinology: The Endocrine Pancreas. Medical College of Georgia. pp. page 16. http://www.lib.mcg.edu/edu/eshuphysio/program/section5/5ch4/s5ch4_16.htm. Retrieved 2008-02-19.
- ^ Costanzo, Linda S. (2003). Physiology (3rd ed.). Hagerstown, MD: Lippincott Williams & Wilkins. pp. 280. ISBN 0-7817-3919-5.
- ^ a b Bowen R (2002-12-14). "Somatostatin". Biomedical Hypertextbooks. Colorado State University. http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/otherendo/somatostatin.html. Retrieved 2008-02-19.
- ^ a b Costoff A. "Sect. 5, Ch. 4: Structure, Synthesis, and Secretion of Somatostatin". Endocrinology: The Endocrine Pancreas. Medical College of Georgia. pp. page 17. http://www.lib.mcg.edu/edu/eshuphysio/program/section5/5ch4/s5ch4_17.htm. Retrieved 2008-02-19.
Further reading
- Florio T, Schettini G (2002). "[Somatostatin and its receptors. Role in the control of cell proliferation]". Minerva Endocrinol. 26 (3): 91–102. PMID 11753230.
- Yamada Y, Reisine T, Law SF, et al. (1993). "Somatostatin receptors, an expanding gene family: cloning and functional characterization of human SSTR3, a protein coupled to adenylyl cyclase". Mol. Endocrinol. 6 (12): 2136–42. doi:. PMID 1337145.
- Yamada Y, Post SR, Wang K, et al. (1992). "Cloning and functional characterization of a family of human and mouse somatostatin receptors expressed in brain, gastrointestinal tract, and kidney". Proc. Natl. Acad. Sci. U.S.A. 89 (1): 251–5. doi:. PMID 1346068.
- Brazeau P, Vale W, Burgus R, et al. (1973). "Hypothalamic polypeptide that inhibits the secretion of immunoreactive pituitary growth hormone". Science 179 (68): 77–9. doi:. PMID 4682131.
- Shen LP, Pictet RL, Rutter WJ (1982). "Human somatostatin I: sequence of the cDNA". Proc. Natl. Acad. Sci. U.S.A. 79 (15): 4575–9. doi:. PMID 6126875.
- Shen LP, Rutter WJ (1984). "Sequence of the human somatostatin I gene". Science 224 (4645): 168–71. doi:. PMID 6142531.
- Montminy MR, Goodman RH, Horovitch SJ, Habener JF (1984). "Primary structure of the gene encoding rat preprosomatostatin". Proc. Natl. Acad. Sci. U.S.A. 81 (11): 3337–40. doi:. PMID 6145156.
- Zabel BU, Naylor SL, Sakaguchi AY, et al. (1984). "High-resolution chromosomal localization of human genes for amylase, proopiomelanocortin, somatostatin, and a DNA fragment (D3S1) by in situ hybridization". Proc. Natl. Acad. Sci. U.S.A. 80 (22): 6932–6. doi:. PMID 6196780.
- Panetta R, Greenwood MT, Warszynska A, et al. (1994). "Molecular cloning, functional characterization, and chromosomal localization of a human somatostatin receptor (somatostatin receptor type 5) with preferential affinity for somatostatin-28". Mol. Pharmacol. 45 (3): 417–27. PMID 7908405.
- Demchyshyn LL, Srikant CB, Sunahara RK, et al. (1993). "Cloning and expression of a human somatostatin-14-selective receptor variant (somatostatin receptor 4) located on chromosome 20". Mol. Pharmacol. 43 (6): 894–901. PMID 8100352.
- Kaupmann K, Bruns C, Hoyer D, et al. (1993). "Distribution and second messenger coupling of four somatostatin receptor subtypes expressed in brain". FEBS Lett. 331 (1-2): 53–9. doi:. PMID 8405411.
- Aguila MC, Rodriguez AM, Aguila-Mansilla HN, Lee WT (1996). "Somatostatin antisense oligodeoxynucleotide-mediated stimulation of lymphocyte proliferation in culture". Endocrinology 137 (5): 1585–90. doi:. PMID 8612489.
- Sharma K, Patel YC, Srikant CB (1997). "Subtype-selective induction of wild-type p53 and apoptosis, but not cell cycle arrest, by human somatostatin receptor 3". Mol. Endocrinol. 10 (12): 1688–96. doi:. PMID 8961277.
- Dournaud P, Boudin H, Schonbrunn A, et al. (1998). "Interrelationships between somatostatin sst2A receptors and somatostatin-containing axons in rat brain: evidence for regulation of cell surface receptors by endogenous somatostatin". J. Neurosci. 18 (3): 1056–71. PMID 9437026.
- Barnea A, Roberts J, Ho RH (1999). "Evidence for a synergistic effect of the HIV-1 envelope protein gp120 and brain-derived neurotrophic factor (BDNF) leading to enhanced expression of somatostatin neurons in aggregate cultures derived from the human fetal cortex". Brain Res. 815 (2): 349–57. doi:. PMID 9878821.
- Ferone D, van Hagen PM, van Koetsveld PM, et al. (1999). "In vitro characterization of somatostatin receptors in the human thymus and effects of somatostatin and octreotide on cultured thymic epithelial cells". Endocrinology 140 (1): 373–80. doi:. PMID 9886848.
- Brakch N, Lazar N, Panchal M, et al. (2002). "The somatostatin-28(1-12)-NPAMAP sequence: an essential helical-promoting motif governing prosomatostatin processing at mono- and dibasic sites". Biochemistry 41 (5): 1630–9. doi:. PMID 11814357.
- Oomen SP, van Hennik PB, Antonissen C, et al. (2002). "Somatostatin is a selective chemoattractant for primitive (CD34(+)) hematopoietic progenitor cells". Exp. Hematol. 30 (2): 116–25. doi:. PMID 11823046.
- Simonetti M, Di BC (2002). "Structural motifs in the maturation process of peptide hormones. The somatostatin precursor. I. A CD conformational study". J. Pept. Sci. 8 (2): 66–79. doi:. PMID 11860030.
|
|||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||||||||||
|
||||||||||||||
|
||||||||||||||||||||||||||
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
Learn More
 | GIH |
| octreotide |
| inhibiting factor |
 | What is the function of somatostatin? Read answer... |
| What is somatostatin's effect on the human body? Read answer... |
| Is somatostatin a polar molecule? Read answer... |
Post a question - any question - to the WikiAnswers community:
Copyrights:
 |
 | Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved. Read more |
 |
| Sci-Tech Encyclopedia. McGraw-Hill Encyclopedia of Science and Technology. Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved. Read more |
 |
| Sports Science and Medicine. The Oxford Dictionary of Sports Science & Medicine. Copyright © Michael Kent 1998, 2006, 2007. All rights reserved. Read more |
 |
| Veterinary Dictionary. Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved. Read more |
 |
| Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Somatostatin". Read more |
Related answers
- What is the function of somatostatin?
- What is somatostatin's effect on the human body?
- Is somatostatin a polar molecule?
ADVERTISEMENT
Mentioned in
- gastroenteropancreatic
- What are some major neurotransmitters? (anatomy)
- gastrointestinal
- islet
- Pituitary Tumors: Treatment
- Pituitary gland disorders (noninfectious diseases)
- hormone
- hormone (material – in anatomy)
- Gastrinoma: Diagnosis
- Pancreatic Cancer, Endocrine: Diagnosis
