Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Filiform polyposis (FP) is a rare condition of uncertain pathogenesis, 28 cases of which have been published since it was first described in 1965. It is usually found in association with chronic inflammatory bowel disease, especially Crohn's disease and ulcerative colitis. The condition is characterized by the presence of numerous, densely packed, filiform polyps in the colon, which may resemble villous adenomas on endoscopy. We describe a case of FP occurring in a 33-year-old man with a 5-year history of Crohn's disease, in whom subtotal colectomy was performed because of perforation of the sigmoid colon. Microscopy revealed inflammatory pseudopolyps covered by largely normal and non-dysplastic colonic epithelium. The neuroendocrine system of the intestine in FP was investigated for the first time in this case: marked hyperplasia of endocrine cells immunoreactive for serotonin, somatostatin and enteroglucagon and of neural structures immunoreactive for substance P and vasoactive intestinal peptide was noted in the polyps and the adjacent intestinal mucosa. The patient has experienced no further complications in the 12 months since the operation. Medication administered in FP depends mainly on the nature of the underlying disease, and the amount of information published about this condition is as yet insufficient to allow any one specific type of treatment to be recommended. FP alone is not an indication for bowel resection but complications, such as massive haemorrhage or intestinal obstruction, may necessitate surgical intervention.
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PMID:Filiform polyposis: a case report describing clinical, morphological, and immunohistochemical findings. 139 19

Neurogenic inflammation is a reaction which includes vasodilation, plasma extravasation, and smooth muscle contraction elicited by activation of and release of mediators from unmyelinated afferent nerve endings. Further release of inflammatory mediators follows activation of axon collaterals associated with these afferent nerve endings as axon reflexes. Substance P, somatostatin, vasoactive intestinal polypeptide, and calcitonin gene-related peptide are candidate mediators. Recent evidence suggests that several of these peptides may be colocalized either with one or more other peptides or with acetylcholine or noradrenalin. Communicating pathways exist between nerves within the mucosa and the muscle layers. Both long and short visceral reflexes occur. Inflammatory, mechanical, or chemical stimuli reaching the mucosa may release peptides from peripheral nerve endings. Thus neurogenic inflammation may be an important factor in inflammatory bowel disease.
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PMID:Neuropeptides, inflammation, and motility. 244 99

To study the effect of mucosal inflammation on tissue concentrations of somatostatin, the distribution and concentration of somatostatin in specimens of normal and abnormal (ulcerative colitis and Crohn's disease) ileum and colon were determined by a specific radioimmunoassay. Each tissue specimen obtained at surgery was separated by microdissection into the mucosa-submucosa and the muscularis externa. Immunoreactive somatostatin was acid-extracted from each layer before measurement. Gel chromatography was used to characterize immunoreactive somatostatin measured by radioimmunoassay; somatostatin-28 was the major immunoreactive species measured in human intestine. In normal colon, concentrations of somatostatin were not related to patient age. Concentrations of immunoreactive somatostatin in the mucosa-submucosa of the descending colon were significantly decreased in ulcerative colitis and in Crohn's colitis, compared with normal colon. There was no apparent relationship between concentrations of somatostatin and the duration of inflammatory bowel disease. However, somatostatin concentrations appeared to be lower in patients with severe colitis than in patients with minimal colitis. The decrease in mucosal-submucosal concentrations of somatostatin is in agreement with previous morphologic studies, which have suggested diminished populations of endocrine cells in ulcerative colitis. The possible role of somatostatin in the colon suggests that further studies of the alteration of this gut peptide may be useful in understanding a component of the pathophysiology of idiopathic inflammatory bowel disease.
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PMID:Somatostatin in the idiopathic inflammatory bowel diseases. 289 35

The circadian (24 hour) rhythmicity of somatostatin in healthy subjects and patients with ulcerative colitis (UC) was studied and established. UC patients were found to have a higher 24-hour amplitude, a higher average level and a longer peak level phase of plasma somatostatin. This finding may indicate a defensive role of somatostatin in inflammatory bowel disease.
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PMID:Plasma somatostatin levels in ulcerative colitis. 772 Dec 43

The multiple actions of somatostatin are mediated by specific membrane-bound receptors present in all somatostatin target tissues, such as brain, pituitary, pancreas, gastrointestinal tract, and kidney. For instance, in the human gastrointestinal tract, three different types of tissue compartments express somatostatin receptors: the gastrointestinal mucosa, the peripheral nervous system, and the gut-associated lymphoid tissue, where the receptors are preferentially located in germinal centers. In all these cases, somatostatin binding is of high affinity and specific for bioactive somatostatin analogues. Somatostatin receptors are also expressed in pathological states, such as cancers. A particular abundance is found in neuroendocrine tumors of the gastrointestinal tract. Ninety percent of the carcinoids and a majority of islet cell carcinomas, including their metastases, usually have a high density of somatostatin receptors. Several different somatostatin-receptor subtypes can be expressed by these tumors, the SSTR2 subtype being the most frequently and abundantly expressed. The somatostatin receptors in tumors are identified with in vitro-binding methods, molecular biology techniques, or in vivo-imaging techniques; the latter allow the precise localization of the tumors and their metastases in the patients. Because somatostatin receptors in human gastroenteropancreatic tumors are functional, their identification can be used to predict the therapeutical efficacy of octreotide to inhibit excessive hormone release. Of differential diagnostic importance is the fact that other pathological processes in the gastrointestinal tract may be associated with a high density of somatostatin receptors. Ninety percent of lymphomas, including those with intestinal involvement express somatostatin receptors. Furthermore, a moderate number of colorectal carcinomas contain somatostatin receptors, whereas exocrine pancreatic carcinomas do not. Finally, an increased expression of SS receptors in nonneoplastic conditions, such as in intestinal veins in inflammatory bowel disease, has been recently observed. These observations demonstrate the ability of the human body to regulate SS receptors in a wide number of tissues and conditions.
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PMID:Expression of somatostatin receptors in normal, inflamed, and neoplastic human gastrointestinal tissues. 797 60

The effect of octreotide, a synthetic analogue of somatostatin, on the modulation of the acetic acid model of experimental colitis was examined. Colitis was induced by intracolonic administration of 2 ml of 5% acetic acid. The inflammatory response elicited by the acetic acid resulted in increased colonic synthesis of platelet activating factor, leukotriene B4 and decreased mucosal somatostatin levels. Subcutaneous administration of octreotide (10 micrograms/rat) 1 hour before or immediately after damage induction, as well as 1 and 23 hours after acetic acid application, resulted in a significant reduction in mucosal damage. The protective effect was accompanied by a significant reduction in platelet activating factor activity, leukotriene B4, and vasoactive intestinal peptide concentrations. There were no significant changes in mucosal leukotriene C4 and calcitonin gene related peptide levels. This study shows that acetic acid induced colitis is pharmacologically manipulated by octreotide. The mechanism of action of octreotide has not yet been fully determined. The potential use of octreotide in treating active inflammatory bowel disease remains to be evaluated.
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PMID:Octreotide effectively decreases mucosal damage in experimental colitis. 838 60

Basal and postprandial concentrations of gastrointestinal hormones were measured in 12 dogs before and at one and three months after a 75% small bowel resection. Five animals were studied again at six months. Concentrations of enteric hormones and neuropeptides, measured in the proximal jejunum and distal ileum adjacent to the anastomotic site at the time of euthanasia, were compared with concentrations in control tissues taken from each animal at the time of resection. Increased basal and postprandial levels of gastrin (P < 0.05), cholecystokinin (CCK, P < 0.05), glucose-dependent insulinotropic peptide (GIP, P < 0.01), peptide YY (PYY, P < 0.001), and enteroglucagon (P < 0.001), were seen at one month after small bowel resection. In contrast, no significant changes were seen in concentrations of secretin, motilin, neurotensin, somatostatin, PP, or glucagon. Concentrations of enteroglucagon, GIP, and PYY remained high throughout the six-month study period. In contrast, gastrin and CCK had normalized by three months. Thus, only enteroglucagon, PYY, and GIP showed sustained elevations following enterectomy; the gastrin and CCK changes were transient. Following enterectomy, concentrations of vasoactive intestinal polypeptide (VIP) were reduced by about 50% in mucosal (P < 0.001) and muscle (P < 0.05) layers of proximal and distal gut. In contrast, calcitonin gene-related peptide (CGRP) was increased by about twofold in jejunal and ileal mucosa (P < 0.05), and CGRP elevations were even more marked in the muscle layers (P < 0.001). Somatostatin and neuropeptide Y (NPY) concentrations were similar to controls in all areas except for a small decrease in NPY in ileal mucosa (P < 0.05). These findings suggest that the increased motilin and PP concentrations previously reported after bowel resection in man are more likely to reflect underlying inflammatory bowel disease rather than enterectomy. The normalization of hypergastrinemia explains why the increased acid secretion after small bowel resection is transient. These results provide evidence for independent secretory control of enteroglucagon and PYY, which are both products of intestinal L cells. In addition, these studies reveal marked changes in enteric neuropeptide concentrations following bowel resection. VIP, which is thought to be a major inhibitory transmitter in the gut, is markedly reduced, while CGRP, which is mainly localized in sensory afferent fibers, is increased. These major neuropeptide changes are likely to be of importance in the adaptive responses to massive small bowel resection.
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PMID:Time course of adaptive regulatory peptide changes following massive small bowel resection in the dog. 865 52

Gastrointestinal fistulas are unfortunate complications of a number of disease states, such as inflammatory bowel disease and tumors, or may result from complications of surgical intervention. Fistulas may be associated with significant morbidity and mortality, much of which is a result of fluid losses and electrolyte imbalances. Thus, attention to these issues is a critical component of the management of patients with gastrointestinal fistulas. The management of gastrointestinal fistulas is divided into three phases: diagnosis/recognition, stabilization/investigation, and treatment. The major goal of the stabilization phase is the correction of fluid losses and electrolyte abnormalities. This phase must be carried out expeditiously to reduce the associated complications. Knowledge of the electrolyte content of various secretions of the gastrointestinal tract is essential to guide this phase of management. Early control of infectious foci, with drainage of abscesses if present, is of great importance. Esophageal fistulas most commonly result from instrumentation of the esophagus and are diagnosed by radiographic imaging studies. Nonoperative therapy is an option in select patients, but aggressive surgical intervention is often required. Dehydration is often associated with these injuries and must be corrected. Gastric and duodenal fistulas are most commonly iatrogenic and may be associated with significant fluid losses. Careful measurement of the fistula effluent is important. Nutritional support is begun following correction of fluid and electrolyte abnormalities. Pancreatic fistulas are often high volume fistulas and are associated with significant skin breakdown if they are cutaneous. The use of a somatostatin analogue may decrease the volume of the fistula to allow healing. Small intestinal fistulas often result from postoperative complications and require careful attention to electrolyte abnormalities. Spontaneous closure often obviates surgical intervention. Colonic fistulas are less often associated with complications than are other fistulas of the gastrointestinal tract. The stabilization phase in the management of patients with gastrointestinal fistulas is a critical time during which careful attention to fluid and electrolyte losses can result in reduced morbidity and mortality from these difficult management problems.
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PMID:General management of gastrointestinal fistulas. Recognition, stabilization, and correction of fluid and electrolyte imbalances. 884 62

Regulatory neuropeptides are widely distributed in the gastrointestinal tract, where they play an important role in motility, secretion, and immune and inflammatory responses. In this study, the rectal mucosal content of somatostatin (SOM), substance P (SP), beta-endorphin (BE), and thyrotropin-releasing hormone (TRH) was measured by radioimmunoassay in 56 patients with ulcerative colitis (UC), 15 patients with Crohn's disease (CD), 15 patients with acute infectious colitis (AIC), and 11 controls, who showed no inflammation of the rectal mucosa, nor abnormal bowel movements. The content of immunoreactive (ir)-SOM was decreased in UC patients, especially in those with persistent disease activity, while the levels of ir-SP, BE, and TRH were increased in such patients. Some changes of ir-peptide levels were also observed in CD and AIC patients. The changes in neuropeptide levels were analyzed in relation to histological grades of inflammation in UC patients, grades 4-5 showing the most significant changes. The levels of ir-SOM, SP, BE, and TRH showed no significant change in chronic persistent UC when measured 6-12 months after the initial examination. In contrast, in patients with remitting intermittent UC, the levels of SP and BE decreased during remission. Abnormal intestinal neuropeptide content may be implicated in the continued mucosal immune and inflammatory responses that are manifested in patients with inflammatory bowel disease.
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PMID:Abnormal neuropeptide concentration in rectal mucosa of patients with inflammatory bowel disease. 884 73

We describe a patient with eosinophilic gastroenteritis whose symptoms included severe watery diarrhea (1.5 l/d), abdominal cramps, and weight loss. Biopsies revealed massive eosinophilic inflammation of the entire gastrointestinal tract. The total plasma eosinophilic count was elevated by up to 30%. Infectious etiologies and chronic inflammatory bowel disease had been ruled out. By use of the somatostatin analogue octreotide the diarrhea decreased immediately in a dose-dependent fashion and the patient recovered within twelve days. In this case octreotide was helpful in controlling severe diarrhea and limiting the subsequent necessary i.v. fluid replacement.
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PMID:[Symptomatic therapy of severe diarrhea in eosinophilic gastroenteritis with the somatostatin analog octreotide (Sandostatin)]. 928 42


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