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)

In addition to established gastrointestinal hormones--secretin, cholecystokinin-pancreozymin (CCK-PZ), gastrin, and glucagon---some 30 polypeptides with gastrointestinal actions can be listed. New aspects of these substances include the following: Gastrin and vasoactive intestinal peptide (VIP) can be also encountered in the central nervous system and may act as transmitters. CCK-PZ-serum concentrations are found markedly elevated in patients with exocrine pancreatic insufficiency; this may provide the opportunity to establish a realtively simple screening test. Moreover, there is evidence that serum-CCK-PZ levels serve as satiety signal. Secretin secretion is said to be enhanced in hunger and then to act as a lipolytic hormone. In addition to enteroglucagon, a gastrintestinal peptide identical to pancreatic glucagon has been detected. Gastric inhibitory polypeptide (GIP) inhibits gastric secretion and motility (enterogastrone activity) and together with glucose it stimulates insulin release (incretin activity). Motilin increases lower esophageal sphincter pressure, enhances gastric pepsin secretion and slows down gastric evacuation. Serum levels of pancreatic polypeptide may be found elevated as a diagnostic index in patients with endocrine peptide tumors of the pancreas. Recently, the potential importance of local (paracrine) actions of gastrointestinal polypeptides has been amphasized. Predominantly paracrine activity is exhibited by some prototype hormones, e.g. somatostatin, substance P, bombesian, and the non-polypeptide compounds, prostaglandins.
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PMID:[New views on gastrointestinal hormones]. 85 99

A case of duodenal somatostatinoma is described in a patient with Von Recklinghausen neurofibromatosis. The patient presented with exocrine pancreatic insufficiency, probably due to distal obstruction of the pancreatic duct by the tumor. Preoperative evaluation with calcium-pentagastrin and tolbutamide stimulation tests were nondiagnostic. At laparotomy, local excision of the tumor was performed. Pathological findings were compatible with duodenal somatostatinoma, causing pancreatic fibrosis. Somatostatin extracted from the tumor coeluted with the somatostatin-14 standard on high performance liquid chromatography (HPLC).
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PMID:Exocrine pancreatic insufficiency and pancreatic fibrosis due to duodenal somatostatinoma in a patient with neurofibromatosis. 134 57

Cholecystokinin (CCK) has been shown to be a powerful stimulus for somatostatin release from isolated canine fundic D-cells in short-term culture. The influence of the CCK analogue caerulein on the secretory activity of the D-cell in the intact stomach in vitro and the effect of elevated plasma levels of endogenous CCK on gastric somatostatin stores in vivo were investigated in the rat. Basal somatostatin secretion from the isolated, vascularly perfused rat stomach preparation was not affected by various doses of caerulein. Slight stimulation of somatostatin-like immunoreactivity (SLI) release by epinephrine was significantly inhibited by caerulein, whereas caerulein did not alter half-maximal stimulation of SLI secretion by isoproterenol. Rats with chronically elevated plasma CCK levels induced by experimental exocrine pancreatic insufficiency did not show any change in tissue concentrations of SLI or in D-cell number, both in the antrum and corpus. These data suggest that CCK--in contrast to dogs--is not an important modulator of gastric somatostatin in the rat.
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PMID:Role of cholecystokinin in the control of gastric somatostatin in the rat: in vivo and in vitro studies. 167 97

The effect of the long-acting somatostatin analogue Sandostatin (SMS 201-995) on intestinal absorption and propagation (mouth-to-caecum transit time; MCTT), on pancreatic secretion and on gall bladder contraction after direct (secretin-pancreozymin test) and indirect stimulation (Lundh meal), and on meal-induced responses of seven gastrointestinal regulatory peptides has been investigated. In a double-blind cross-over study, 9 healthy volunteers completed two 7-day periods with subcutaneous injections of either placebo or 25 micrograms SMS 201-995 twice daily. Mean faecal fat excretion was increased to 19.2 g/day and MCTT was three times longer during the SMS period. After duodenal infusion of a mixture containing D-galactose, D-xylose and triglycerides, SMS 201-995 significantly reduced the serum concentrations of D-galactose but increased serum levels of D-xylose. After 6 days of pretreatment, SMS 201-995 completely suppressed duodenal trypsin, lipase and bilirubin increases in response to endogenous stimulation by a Lundh meal. Concomitantly, cholecystokinin (CCK) release and gall bladder contraction were almost abolished. Compared with placebo, SMS 201-995 significantly diminished pancreatic amylase, trypsin and lipase output after stimulation with CCK, while the secretion of fluid and bicarbonate in response to secretin was unchanged. This inhibition of enzyme response was significantly more marked after a single injection of the analogue than after pretreatment for 7 days and did not reach the level of exocrine pancreatic insufficiency. CCK-induced gall bladder contraction was significantly inhibited by a single dose of 25 micrograms SMS 201-995 but not after 7 days of pretreatment with the somatostatin analogue.
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PMID:Effect of the somatostatin analogue sandostatin (SMS 201-995) on gastrointestinal, pancreatic and biliary function and hormone release in normal men. 288 60

A new technique to obstruct the pancreatic ducts was developed by injecting zein solution into the common bile duct of the rat. Four weeks after the injection, the fate of the endocrine pancreas was investigated by studying (a) pancreatic content of four pancreatic hormones, (b) histology and immunohistochemistry of the pancreas, (c) i.v. glucose tolerance and i.v. insulin tolerance tests for monitoring plasma glucose, insulin, and pancreatic polypeptide (PP) levels in vivo, and (d) in vitro perifusion of pancreatic tissue slices to assess insulin and PP secretion. In zein-injected rats, the total pancreatic content of insulin, glucagon, PP, and somatostatin was reduced to 80, 70, 40, and 20%, respectively, of the corresponding controls. In response to insulin-induced hypoglycemia, the plasma PP levels rose to about one-half that of the controls. By contrast, perifused zein-injected rat pancreases released several times more PP than the controls in response to carbachol stimulation. In zein-injected rats, total pancreatic protein was reduced to 20% of the controls and pancreatic amylase was almost absent, reflecting practically complete loss of acinar tissue. Thus, this experimental model appears to be suitable for producing chronic pancreatic insufficiency in the rat and provides a useful model for studying both endocrine and exocrine functions in the small rodent.
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PMID:Endocrine pancreas in the rat model of exocrine pancreatic insufficiency. 305 70

A pancreatic somatostatinoma metastatized to the liver was detected in a 70-yr-old woman presenting with chronic diarrhea, steatorrhea, pancreatic insufficiency, diabetes mellitus, and achlorhydria. At immunocytochemistry, most tumor cells stored both somatostatin and calcitoninlike substances. Chromatography of acid extracts of the tumor on G50 Sephadex gave two distinct peaks coeluting with cyclic ovine somatostatin and human calcitonin, respectively, thus ruling out the hypothesis of a single cross-reacting molecule synthetized by the neoplastic cells. When the tumor was extracted at neutral pH, larger molecular forms of the above components were found, which accounted for less than 20% of the total immunoreactivity. Gel permeation of plasma showed that the circulating calcitonin- and somatostatinlike components consisted of three and four different forms, respectively, including components of molecular weights similar to those of the reference peptides. Inhibition curves and immunoadsorption experiments indicated that the large forms were immunologically similar, if not identical, to the corresponding standard preparations. The present case illustrates the occasional ability of neoplastic somatostatin cells of pancreas to synthetize simultaneously components immunologically related to somatostatin and calcitonin. These two inappropriate secretions could account for the symptoms displayed by this patient.
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PMID:Calcitonin-producing pancreatic somatostatinoma. 610 50

Regulation of pancreatic exocrine secretion is comprised of a complex interplay between hormonal and nervous mechanisms. Stimulatory gut hormones which act via the circulation include secretin, CCK, gastrin and bombesin, while VIP operates through peptidergic nervous release. Pancreatic polypeptide and glucagon are two examples of circulating inhibitory hormones while inhibition by somatostatin is through a paracrine release mechanism. Although the effects of vagal cholinergic nerves have been previously thought to be indirect through hormone release evidence is now accumulating for a direct role. Altered hormone release has been noted in chronic pancreatic insufficiency, cystic fibrosis and coeliac disease and may contribute in an important way to the pathophysiology of these malabsorptive disorders.
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PMID:Neuro-hormonal control of pancreatic function in man and its failure. 613 50

A case of somatostatin and pancreatic polypeptide (PP) producing tumor of the pancreas is presented. A 65-year-old woman was admitted for the evaluation of the tumor in the right upper quadrant of the abdomen. Clinical abnormalities included diabetic glucose intolerance, pancreatic insufficiency and marked dilatation of gallbladder. Marked high concentration of plasma PP and low levels of plasma insulin and glucagon were observed before operation. Plasma insulin concentrations in response to oral glucose tolerance test and arginine infusion were markedly low. A large quantity of somatostatin (4,300 ng/g ww) as well as PP (1,340 ng/g ww) was detected in the tumor, and somatostatin cells and PP cells were determined by immunofluorescence studies. After operation, pancreatic insufficiency and glucose intolerance were improved, and the patient made a favorable progress.
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PMID:Somatostatinoma syndrome accompanied by overproduction of pancreatic polypeptide. 614 97

The mucosal concentrations of seven regulatory peptides and the density properties and integrity of their storage granules have been studied in mucosal biopsies from the human jejunum in eight gastrointestinal disease states and compared with normal controls. In diseases with associated mucosal inflammation (coeliac disease, Crohn's disease with jejunal involvement, postinfective tropical malabsorption, and common variable immunodeficiency) there was a selective increase in fragility of the gastric inhibitory polypeptide (GIP) and somatostatin storage granules. The gastrin, motilin, enteroglucagon, secretin, and vasoactive intestinal polypeptide granules had normal properties in these conditions. In diseases in which diarrhoea occurred in the absence of changes in jejunal mucosal histology (irritable bowel syndrome, pancreatic insufficiency, jejuno-ileal bypass for morbid obesity, and purgative abuse) there were no abnormalities of the storage granules. Increased mucosal concentrations of all peptides except vasoactive intestinal polypeptide (VIP) were found in coeliac disease and selective increases of VIP found in Crohn's disease, motilin in the irritable bowel syndrome and gastrin and GIP in pancreatic insufficiency. It is suggested that the storage granule abnormalities in the diseases with abnormal mucosal histology are secondary to the inflammatory changes.
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PMID:Gastrointestinal regulatory peptide storage granule abnormalities in jejunal mucosal diseases. 614 62

A 74-year-old male suffering from Recklinghausen's fibromatosis (NvR) is reported. He presented with weight loss, cholestasis, endocrine and exocrine pancreatic insufficiency. These symptoms were caused by a neuroendocrine tumor of the ampulla of Vater containing somatostatin. The tumor induced an obstruction of both the common bile and the pancreatic duct. In addition to this uncommon tumor, a silent pheochromocytoma was found. The patient was treated by endoscopic papillotomy, substitution of pancreatic enzymes and additional enteral nutrition. After recovery no progression of the disease was observed over one year. A review of the literature shows that patients with neurofibromatosis are at high risk for periampullar tumors. In particular, somatostatin-rich carcinoids were previously documented. Pheochromocytomas are also quite prevalent in NvR. However the combination of NvR, pheochromocytoma and somatostatin-rich neuroendocrine tumors of the duodenum has only been reported a few times. An explanation for the high prevalence of neuroendocrine tumors in NvR might be the loss of neurofibromin, a tumor suppressor protein, which is the main product of the neurofibromatosis-l-gene.
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PMID:[A rare combination of pheochromocytoma ans somatostatin-rich neuroendocrine tumor of Vater's papilla (carcinoid) in a patient with von Recklinghausen neurofibromatosis]. 957 7


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