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

Peptides such as somatostatin (SS14), epidermal growth factor (EGF), transforming growth factor-alpha (TGF alpha), and insulin-like growth factors (IGF-I and IGF-II) are present in breast milk from various species, and their significance in the developing gastrointestinal tract has been suggested. Our recent studies have indicated that rat milk soluble fraction (RMSF) protects SS14 in the gastrointestinal lumen by inhibiting in vitro the luminal peptidolysis. In the present studies, we have shown that RMSF inhibited in vitro degradation by midjejunal luminal flushings of suckling rats of 125I-labeled somatostatin 14[Tyr11], EGF, TGF alpha, IGF-I and IGF-II, as well as trypsin activity in vitro against benzoyl-L-arginyl-p-nitroanilide. The inhibitory factors present in the RMSF were further fractionated by gel filtration on Sephadex G100, ion-exchange chromatography on DEAE-Sephadex, and fast protein liquid chromatography (FPLC). Gel filtration of Sephadex G100 separated RMSF into three peaks of proteins: G1, G2, and G3; peptidase inhibitor activities were present exclusively in G1. Ion-exchange chromatography on DEAE-Sephadex column resolved peptidase inhibitory activity (G1) into three different peaks, D1, D2, and D3, eluted at sodium chloride concentrations of 0.05 M, 0.1 M, and 0.2 M, respectively. Further purification of D2 by FPLC resulted in a fraction rich in peptidase inhibitory activity, which was essentially free of trypsin inhibitory activity. Results indicate the presence of at least three peptidase inhibitors in rat milk, which may play a role in the protection of milk-borne peptides in the gastrointestinal lumen.
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PMID:Presence of multiple forms of peptidase inhibitors in rat milk. 814 98

Activation of type A receptors by CCK or cerulein is known to stimulate pancreatic enzyme secretion, but its role in the amino acid (AA) consumption and enzyme synthesis remains unclear. In our study, we used loxiglumide, a potent CCK-A-receptor antagonist, to investigate the role of CCK-A receptors in pancreatic consumption of circulating AAs and enzyme secretion. Five healthy male volunteers were intubated with double-lumen duodenal tube, and duodenal aspirates were collected during 60-min basal periods and then during pancreatic stimulation with iv infusion of secretion (80 pmol/kg/h) plus cerulein (50 pmol/kg/h) during three consecutive 30-min periods. The same procedure was repeated, but secretin-cerulein infusion was combined with a constant dose of loxiglumide (20 mumol/kg/h). The volume and outputs of HCO3-, protein and enzymes (amylase and trypsin) in duodenal aspirates and gallbladder volume (by sonography) were determined at 30-min intervals. Plasma samples were drawn for total plasma AA assay by ninhydrin method to assess the pancreatic uptake of free AAs. Infusion of secretin plus cerulein caused a several-fold increase in the volume of duodenal aspirate and the outputs of HCO3-, protein, and enzymes. During those periods, plasma AA level decreased from initially 2.20 +/- 0.3 mmol/L to 1.09 +/- 0.3 mmol/L (p < 0.01) and the gallbladder volume from initially 28 +/- 8 mL to 2 +/- 0.4 mL. This increase in pancreatic secretory outputs was accompanied by significant increments in plasma insulin, glucagon, PP, and somatostatin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cholecystokinin (CCK) in the amino acid uptake and enzyme protein secretion by the pancreas in humans. 856 35

Somatostatin is a potent inhibitor of endocrine and exocrine pancreatic secretion. However, it is not clear whether it also inhibits pancreatic growth. Therefore we treated male Wistar rats with a somatostatin analogue, octreotide (12-192 micrograms/(kg body wt.day)), over a period of 14 days. In a dose-dependent manner, this potent and long-acting analogue caused a reduction in weight of the pancreas and a reduction in pancreatic content of protein, DNA, trypsin, chymotrypsin, amylase and lipase, as well as pancreatic content of insulin-, glucagon- and somatostatin-like immunoreactivities. When growth of rat pancreas was induced by oral administration of camostate (200 mg/(kg body wt. day) or by subcutaneous administration of cholecystokinin (2 x 10 micrograms/(kg body wt. day)) over a period of 14 days, octreotide (12-192 micrograms/(kg body wt.day)) had the same effects, but these were even more pronounced. We conclude that somatostatin is an important regulator of pancreatic growth.
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PMID:Rat pancreas after long-term treatment with the somatostatin analogue octreotide. 896 3

Bile salts are intraduodenal stimulants of basal pancreatic secretion. This study aims to show whether the three main bile salts of human bile differ in their action on pancreatic secretion, and whether they enhance or inhibit each other after combined use. Furthermore, the effect on gastroenteropancreatic peptide release is evaluated. Twelve subjects were provided with a gastroduodenal double-lumen tube. Equimolar doses (0.6 mmol) of taurocholate (322 mg), taurodeoxycholate (313 mg), and a combination of both stimuli were given intraduodenally. Another 12 subjects received taurochenodeoxycholate (313 mg) instead of taurocholate. Volume, bicarbonate, trypsin, and lipase were determined in duodenal aspirates. Cholecystokinin, pancreatic polypeptide, and somatostatin were measured radioimmunologically in plasma samples. All bile salts and combinations exerted a significant hydrokinetic and ecbolic effect. The hydrokinetic response of the combined stimuli was significantly higher as compared with taurocholate and taurochenodeoxycholate, respectively. As far as concerns the ecbolic response, the difference was significant only for trypsin output as compared with taurochenodeoxycholate. Plasma cholecystokinin rose significantly only after the combined stimuli. Pancreatic polypeptide and somatostatin increased significantly after all stimuli, except pancreatic polypeptide after taurocholate. Combined use enhances the hydrokinetic and ecbolic effects of single bile salts. Cholecystokinin may, hereby, be involved as a mediator of the ecbolic effect. Pancreatic polypeptide release indicates cholinergic mechanisms as further mediators. As demonstrated by somatostatin release, counter-regulatory mechanisms are also triggered by intraduodenal bile salts.
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PMID:Exocrine pancreatic secretion and plasma levels of cholecystokinin, pancreatic polypeptide, and somatostatin after single and combined intraduodenal application of different bile salts in man. 903 83

The authors investigated the effects of glucagon and a somatostatin preparation (Stilamin) on the secretion volume and on the secreted and absorbed enzyme levels of the pancreas. Four groups of dogs with an artificial pancreatic fistula were given a single intravenous injection of glucagon (group I, n = 8), intravenous drip-infusion of glucagon (group II, n = 8), intravenous drip-infusion of somatostatin (group III, n = 10) and intravenous drip-infusion of the carrier fluid, physiological sodium-chloride (control, group IV, n = 5), respectively. Pancreatic juices were collected and volume, pH, bicarbonate, amilase, lipase, trypsin and protein contents were determined. Serum amilase and lipase levels before and at the termination of the experiment were also measured. Intravenous drip-infusion of both Glucagon and Stilamin decreased pancreatic secretion, Stilamin being more effective than Glucagon. On the other hand, a single i.v. injection of Glucagon resulted in an increased secretion. The authors suggest that based on the observed inhibitory effect on pancreatic secretion, both glucagon and somatostatin could be used to reduce postoperative complications of pancreatic operations in the clinical practice.
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PMID:Effect of glucagon and somatostatin on pancreatic secretion in dogs. 904 60

Pancreatic exocrine secretion and plasma cholecystokinin, gastrin, secretin, and somatostatin concentrations were examined in relation to feeding in 70- to 120-day-old preruminant and ruminant calves. The apparatus used was designed to immediately re-infuse the animal's own pancreatic juice and to carry out accurate measurements of the juice flow in real time and to take samples. In the preruminants, pancreatic juice, protein, and trypsin flows increased from 45 min before and until 15 min after the meal and decreased sharply thereafter over a period of 30 min. while protein and trypsin concentrations peaked after feeding. A significant increase in plasma gastrin and cholecystokinin (CCK), a fall in secretin and no change in somatostatin were observed after milk ingestion. By contrast, in the ruminants, feeding had no effect on the pancreatic secretion and on the plasma concentrations of these peptides. Similar and simultaneous patterns of juice flow and secretin, as well as of protein and trypsin concentrations, CCK and gastrin, could support the hypothesis that these gut regulatory peptides play a significant role in the regulation of the pancreatic function. In preruminant calves, the existence of cephalic, gastric and intestinal phases is discussed. In the ruminants, that of the ruminal phase is questionable.
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PMID:Kinetics of pancreatic exocrine secretion and plasma gut regulatory peptide release in response to feeding in preruminant and ruminant calves. 917 82

Although clusters of pancreatic acinar cells (CPACs) have been reported in gastric mucosa of adults, they have not been described in children. We reviewed 283 pediatric gastric (239 antral and 44 corpus) mucosal biopsies during a 2-year period and detected CPACs in 10 antral biopsy samples. These biopsy samples were stained immunohistochemically for pancreatic exocrine markers (trypsin, chymotrypsin, alpha-amylase, and lipase) and a panel of regulatory substances (insulin, glucagon, somatostatin, pancreatic polypeptide, gastrin, and serotonin). Double immunostaining for colocalization of chromogranins and trypsin as well as mucin and trypsin also were performed on all cases. CPACs were seen in antral mucosa in a background of either normal or minimally inflamed mucosa, without any atrophy or metaplasia, and were positive for all pancreatic exocrine markers. Stray chromogranin-positive cells in the CPACs were also immunopositive for somatostatin, gastrin, or serotonin. All CPACs showed a few hybrid (amphicrine) cells that coexpressed both chromogranin and trypsin. In one case, ultrastructural examination showed such cells to contain both zymogen and neurosecretory granules. Although the presence of CPACs exclusively in the antrum is most likely the result of a sampling bias, the presence of hybrid cells with an amphicrine phenotype suggests that CPACs probably result from an aberration of stem cell differentiation.
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PMID:Pancreatic acinar cell clusters in pediatric gastric mucosa. 942 22

Intraduodenally applied bile salts and essential amino acids are known to stimulate exocrine pancreatic secretion. There are contradictory reports, however, about an interaction of both stimuli with respect to pancreatic function. The intention of the study was to compare the effects of equimolar amounts of taurodeoxycholate and L-phenylalanine used singularly and combined on pancreatic secretion and on gastroenteropancreatic peptide release. In 12 healthy subjects, 0.8 mmol of Na-taurodeoxycholate (410 mg) and L-phenylalanine (130 mg) were separately and combined applied into the duodenum in a randomized order. Volume, bicarbonate, trypsin, lipase, and amylase secretion as well as cholecystokinin, pancreatic polypeptide, and somatostatin plasma levels were measured. Volume and bicarbonate secretion was significantly enhanced by taurodeoxycholate. The effect was stronger compared to L-phenylalanine. The increase of enzyme secretion was comparable. After combined application, the ecbolic effect was insignificantly smaller, whereas the hydrokinetic effect was between those of the single stimuli. Plasma levels of cholecystokinin, pancreatic polypeptide, and somatostatin rose concomitantly with the pancreatic response. On an equimolar basis taurodeoxycholate results in a stronger hydrokinetic effect than L-phenylalanine. Their ecbolic effects, however, are comparable. In addition to cholinergic mechanisms, as indicated by the PP release observed, cholecystokinin may also act as a mediator. In combined application, the stimuli interfere with each other. Somatostatin and pancreatic polypeptide are not responsible for this mutual inhibition.
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PMID:Effect of intraduodenal taurodeoxycholate and L-phenylalanine on pancreatic secretion and on gastroenteropancreatic peptide release in man. 943 49

In vitro studies have been performed to demonstrate and characterize specific binding sites for synthetic GH secretagogues (sGHS) on membranes from pituitary gland and different human brain regions. A binding assay for sGHS was established using a peptidyl sGHS (Tyr-Ala-hexarelin) which had been radioiodinated to high specific activity at the Tyr residue. Specific binding sites for 125I-labelled Tyr-Ala-hexarelin were detected mainly in membranes isolated from pituitary gland and hypothalamus, but they were also present in other brain areas such as choroid plexus, cerebral cortex, hippocampus and medulla oblongata with no sex-related differences. In contrast, negligible binding was found in the thalamus, striatum, substantia nigra, cerebellum and corpus callosum. The binding of 125I-labelled Tyr-Ala-hexarelin to membrane-binding sites is a saturable and reversible process, depending on incubation time and pH of the buffer. Scatchard analysis of the binding revealed a finite number of binding sites in the hypothalamus and pituitary gland with a dissociation constant (Kd) of (1.5 +/- 0.3) x 10(-9) and (2.1 +/- 0.4) x 10(-9) mol/l respectively. Receptor activity is sensitive to trypsin and phospholipase C digestion, suggesting that protein and phospholipids are essential for the binding of 125I-labelled Tyr-Ala-hexarelin. The binding of 125I-labelled Tyr-Ala-hexarelin to pituitary and hypothalamic membranes was displaced in a dose-dependent manner by different unlabelled synthetic peptidyl (Tyr-Ala-hexarelin, GHRP2, hexarelin, GHRP6) and non-peptidyl (MK 0677) sGHS. An inhibition of the specific binding was also observed when binding was performed in the presence of [D-Arg1-D-Phe5-D-Trp7,9-Leu11]-substance P, a substance P antagonist that has been found to inhibit GH release in response to sGHS. In contrast, no competition was observed in the presence of other neuropeptides (GHRH, somatostatin, galanin or Met-enkephalin) which have a known influence on GH release. In conclusion, the present data demonstrate that sGHS have specific receptors in human brain and pituitary gland and reinforce the hypothesis that these compounds could be the synthetic counterpart of an endogenous GH secretagogue involved in the neuroendocrine control of GH secretion and possibly in other central activities.
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PMID:Specific receptors for synthetic GH secretagogues in the human brain and pituitary gland. 961 63

Exocrine secretion from the pancreas and concentrations of cholecystokinin, gastrin, secretin, and somatostatin in plasma were measured in relation to feeding in 70- to 120-d-old preruminant calves fed either a milk diet or a soybean diet. Pancreatic fluid was continuously collected, measured, and reintroduced in catheterized calves. Blood samples were withdrawn for measurements of gut regulatory peptide concentrations in plasma. A slight increase in outflow of pancreatic fluid was observed 30 min before the milk diet was introduced but not before the soybean diet was fed. In contrast, concentrations and outflows of protein and trypsin immediately after feeding were higher when calves were fed the soybean diet. Overall, during the first 5 h postfeeding, the outflow of pancreatic fluid was 40% higher when the milk diet was fed than when the soybean diet was fed. No difference in outflow of protein was observed, but that of trypsin was 82% higher when the soybean diet was fed. This enhanced enzyme secretion could have been related to the increased plasma concentrations of gastrin and cholecystokinin after the soybean diet was fed. Secretin release was less in calves fed the milk diet that in calves fed the soybean diet during the first 2 h postfeeding, suggesting that this gut peptide along with gastrin and cholecystokinin, contributed to the stimulation of enzyme secretion. Plasma gut regulatory peptides could be influenced by the soybean diet, which does not coagulate in the stomach, inducing faster gastric emptying of protein and fat, and by the chemical form of protein from the soybean diet and the lower susceptibility of these proteins to protease compared with casein. However, the resulting enhancement of pancreatic trypsin secretion and activity seemed to be insufficient to increase the digestibility of soybean protein up to a level similar to that of milk.
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PMID:Comparison of the kinetics of pancreatic secretion and gut regulatory peptides in the plasma of preruminant calves fed milk or soybean protein. 962 Dec 34


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