somatostatin


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Related to somatostatin: Octreotide

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 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 Endocrine system (vertebrate), Hormone, Neurosecretion, Pituitary gland

somatostatin

[¦sō·məd·ə′stat·ən]
(biochemistry)
A peptide secreted by the hypothalamus which acts primarily to inhibit the release of growth hormone from the anterior pituitary.
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Specificity of somatostatin receptor scintigraphy: A prospective study and effects of false-positive localizations on management in patients with gastrinomas.
The value of somatostatin receptor imaging with In-111 Octreotide and/or Ga-68 DOTATATE in localizing ectopic ACTH producing tumors.
Somatostatin is a regulatory peptide, with affinity for G-protein-coupled membrane-bound SSTR subtypes 1-5, including 2A and 2B, which are overexpressed in NETs.
68]Ga-DOTATOC PET/CT and somatostatin receptor (sst1-sst5) expression in normal human tissue: correlation of sst2 mRNA and [SUV.
Neuroendocrine carcinoma of the ampulla of vater: a case of absence of somatostatin in a vasoactive intestinal polypeptide-, bombesin-, and cholecystokinin-producing tumor.
Nonsurgical treatment choices are somatostatin analogs, radiotherapy, and cabergoline at maximum doses.
Somatostatin is a polypeptide hormone secreted by pancreatic [delta]-cells and hypothalamus where inhibits grown hormone (GH) release [15].
Gastrointestinal hormone concentrations, including motilin (MTL), gastrin (GAS), somatostatin (SS) and vasoactive intestinal peptide (VIP) were determined with commercially available radioimmunoassay (RIA) kits.
These 11 articles describe the most recent research on the configuration, diagnosis and treatment of DR and related conditions, beginning with an examination of diabetic macular edema and an analysis of the three phenotypes of DR and modes of differentiation, instructions on using optical coherence tomography findings in DR, laser treatments, benefits and limitations in vitreoretinal surgery for DR and macular edema, treatment by intravitreal triamcinolone acetonide or by long-acting somatostatin analogue, and the potential use of vascular endothelial growth factor or pharmacologic vitreolysis.
Our previous studies have indicated a direct association between severe hepatic fibrosis and low levels of circulating somatostatin levels in S.
Octreotide acetate is a synthetic somatostatin analogue that binds to somatostatin receptors on somatotroph tumors and inhibits GH synthesis and secretion.

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