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)

The role of gastrointestinal and pancreatic hormones in regulating liver growth was evaluated by measuring their effect on DNA synthesis in the normal and regenerating liver of rats in vivo and in maintenance cultures of adult rat hepatocytes in vitro. After partial liver resection DNA synthesis reached peak levels after 24 hours while serum concentrations of immunoreactive insulin in portal and peripheral blood at this time were still suppressed. Increase of endogenous insulin levels by intravenous glucose infusion or portal infusion of insulin, glucagon or both together with glucose did not change DNA synthesis in normal or regenerating rat liver. After acute carbon tetrachloride poisoning of rats, survival rate and degree of liver necrosis was not changed by intraperitoneal infusion of glucagon and insulin with glucose. In vitro, insulin, glucagon and somatostatin synergistically stimulated the specific thymidine uptake in seven-day-old maintenance cultures of rat hepatocytes. The hormones did not cause cell multiplication but enhanced cell survival, probably by improving the uptake and utilization of nutrients. Gastrin G-17, secretin and cholecystokinin (contaminated with gastric inhibitory polypeptide) had no effect. It is concluded that the results do not support the contention that liver regeneration is regulated by the known pancreatic hormones. However, a trophic effect of pancreatic hormones on liver cells in vitro could be demonstrated. Gastrointestinal hormones had no such effect.
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PMID:Hepatotrophic effects of pancreatic and gastrointestinal hormones in the rat in vivo and in vitro. 24 3

Several gastrointestinal peptides with proven or suggested endocrine or paracrine functions influence gastric acid secretion, gastrointestinal motility, and mucosal blood flow. Increased or decreased release of such factors could participate in the pathogenesis of duodenal ulcer disease by inducing increased gastric acid concentration in the duodenal bulb. To date, increased stimulation of parietal cells by gastrin has been demonstrated only in patients with gastrinoma, G-cell hyperplasia, gastric outlet obstruction, hyperparathyroidism, excluded antrum, and short bowel syndrome, but not in the usual duodenal ulcer disease. Also, a defective inhibition of parietal cell function by endocrine or paracrine factors, such as gastric inhibitory polypeptide, secretin, somatostatin and vasoactive intestinal polypeptide, seems not to exist in patients with duodenal ulcer disease. However, as long as the physiology of gastrointestinal peptides in gastric secretion and motility is not understood, a possible role of these factors in the pathogenesis of simple duodenal ulcer disease cannot be excluded.
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PMID:Endocrinology of duodenal ulcer. 51 78

A reliable, sensitive, reproducible and specific radioimmunoassay for cholecystokinin-pancreozymin (CCK) has been developed, using rabbit antisera to highly purified porcine hormone. The natural occurring variant of CCK (39-CCK), in which the ordinary CCK is lengthened from its N-terminus by a hexapeptide, labelled with 125J, and repurified by column chromatography on Sephadex G-10 and on SP-Sephadex C-25, was used as tracer. Separation from antibody-bound labelled 39-CCK was carried out using a double antibody procedure. Non-specific interference with the assay system was abolished by ethanol extractions. Highly purified porcine CCK was used as standard. No significant crossreaction was found with gastrin, motilin, vasoactive polypeptide (VIP), gastric inhibitory polypeptide (GIP), natural and synthetic secretin, pancreatic glucagon or insulin. The sensitivity of the assay is approximately 40 pg/ml of test solution. The mean immunoreactive CCK concentration in 45 fasting normal subjects was 222 pg/ml increasing after food ingestion to 480 pg/ml. Somatostatin was able to abolish the stimulated CCK release. Elevated CCK concentrations were found in chronic pancreatitis. Immunohistochemical identification of pancreozymin cells was carried out either in surgical samples or in biopsy material. Approximately 1650 CCK cells per cross-section in the duodenum of humans have been found. The CCK cells usually appeared elongated, oval or pyramidal in shape and were observed to reach the lumen with their apical cell pole.
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PMID:Estimation of cholecystokinin-pancreozymin (CCK) in human plasma and tissue by a specific radioimmunoassay and the immunohistochemical identification of pancreozymin-producing cells in the duodenum of humans. 56 41

The effects of gastrin, gastric inhibitory polypeptide, secretin, and the octapeptide of pancreozymin-cholecystokinin on immunoreactive somatostatin release were studied in the isolated perfused dog pancreas. Gastrin at a concentration of 65 ng/ml and the octapeptide of pancreozymin-cholecystokinin at a concentration of 25 ng/ml produced a prompt, but transient statistically significant, twofold rise in mean somatostatin concentration. Secretion at a concentration of 0.3 U/ml and gastric inhibitory polypeptide concentration of 58 ng/ml produced a prompt two- to threefold rise in mean somatostatin release, which persisted throughout the perfusion period. With all four polypeptides the pattern of the somatostatin response resembled that of insulin. It appears that pancreatic somatostatin release is stimulated by gastrointestinal hormones that influence the secretion of insulin and glucagon.
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PMID:The effects of gastrin, gastric inhibitory polypeptide, secretin, and the octapeptide of cholecystokinin upon immunoreactive somatostatin release by the perfused canine pancreas. 90 61

Studies were carried out in conscious dogs in which the effect of intravenous somatostatin on immunoreactive gastric inhibitory polypeptide (IR-GIP) release was investigated. In addition, the inhibitory action of somatostatin on the insulin response to pure porcine GIP was assessed. Intravenous administration of somatostatin resulted in a delayed IR-GIP and immunoreactive insulin (IRI) response to oral glucose. Somatostatin also delayed the IR-GIP response to the ingestion of fat. In both types of experiments, initial depression of IRI levels was followed by a sharp rise in IRI release. Intravenous infusion of somatostatin produced 80% inhibition of the IRI response to pure porcine GIP. It was concluded that somatostatin inhibits the physiological release of IR-GIP and the insulinotropic action of exogenous porcine GIP.
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PMID:The effect of somatostatin on release and insulinotropic action of gastric inhibitory polypeptide. 122 89

To ascertain whether certain gastro-entero-pancreatic hormones whose concentration in blood rises after ingestion of food could play a role in the elevation of plasma triglycerides (or hepatic triglyceride secretion) observed after oral vs parenteral feeding, studies were undertaken of their acute effects upon triglyceride synthesis and release by freshly isolated rat hepatocytes in vitro. The incorporation of radiopalmitate into hepatocyte triglycerides was significantly increased, by one-fourth to one-half, by each of pancreatic polypeptide, peptide YY, and an intermediate concentration (0.50 microgram/mL) of somatostatin. However, at a lower concentration (0.25 microgram/mL) somatostatin significantly decreased (by 14%) the incorporation of radiopalmitate into hepatocyte triglycerides. Release of labelled triglycerides from hepatocytes into the medium was significantly enhanced by both gastric inhibitory polypeptide (by 31%) and pancreatic polypeptide (22%), but was significantly reduced (by 28%) by somatostatin at a concentration of 1 microgram/mL. Neurotensin produced no detectable effect. Although there were similarities between the active hormones, each had a unique overall pattern of response on triglyceride synthesis and release and individually, or in concert with other hormones, could modulate hepatic triglyceride production and secretion, thereby explaining the differential effects of oral vs parenteral feeding on plasma triglycerides.
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PMID:Effects of gastro-entero-pancreatic hormones upon triglyceride synthesis and secretion by rat hepatocytes. 134 74

There is a marked difference in insulin secretion between the ob+/ob+ obese mouse and its non-obese littermate. Numerous peptides have been implicated in the modification of postprandial insulin secretion. In this study, the morphological and immunohistochemical studies of the genetically obese mouse (ob+/ob+) pancreata were compared with control littermates. Additionally, the distribution of gastric inhibitory polypeptide, somatostatin, glucagon, and insulin immunoreactive cells was also quantitated. Hyperglycemia and hyperinsulinemia were verified in the obese mice. The control animals had some islets and ductules with mononuclear infiltrations of a possible immune character. The obese individuals had a marked increase in both number and size of the islets of Langerhans compared with lean controls. The insulin immunocytochemical reaction in the obese pancreatic beta-cells was weaker than that of controls, as was the aldehyde-fuchsin reaction. The glucagon, gastric inhibitory polypeptide, and somatostatin containing cells were intermingled with the beta-cells. In contrast, the control animals showed a peripheral localization of these cell types. The morphometric analysis of the obese pancreas showed a decreased proportion of non-beta cells within the islets but not in total pancreatic volume in comparison with controls. The obese mouse also had cavities filled with eosin-stained material among numerous beta-cells. No complete epithelial lining distinguished these formations from the surrounding islet cells. The content of the cavities was not stained by any of the immunocytochemical reactions applied. In conclusion, the pancreatic islets of the ob+/ob+ mouse show marked differences in both morphological and immunocytochemical characteristics if compared with control littermates. These differences in architecture may be related to the eventual development of diabetes mellitus in the ob+/ob+ mouse.
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PMID:A morphological and immunohistochemical investigation of endocrine pancreata from obese ob+/ob+ mice. 167 42

Gastrointestinal hormones with insulinotropic effects, like cholecystokinin (CCK) and gastric inhibitory polypeptide (GIP) might tentatively be used in the treatment of non-insulin-dependent diabetes mellitus. We therefore examined the effects of intravenous injection of pharmacological dose levels of CCK-8 (100 and 300 pmol/kg), CCK-33 (100 pmol/kg), GIP (100 pmol/kg), and CCK-8 plus GIP (100 pmol/kg of each) on plasma levels of glucose, insulin, somatostatin, glucagon, and pancreatic polypeptide (PP) in healthy human volunteers. The peptides were given under basal conditions or in combination with a mixed meal. CCK-8, CCK-33, and GIP were all found to increase the basal plasma levels of insulin, somatostatin, and PP; the increases were observed already in samples taken at 2 min after the injection. In contrast, the plasma glucagon levels were unaffected by the peptides. CCK-8, CCK-33, and GIP (100 pmol/kg) all potentiated the meal-induced plasma responses of insulin and PP, whereas plasma levels of glucagon after the meal were not affected. Plasma somatostatin levels after the meal were increased by GIP but not affected by CCK-8 or CCK-33. CCK-8 and GIP together (100 pmol/kg for both) increased plasma levels of insulin, PP and somatostatin as much as each of the peptides given alone, both under basal conditions and after the meal intake. Plasma levels of glucagon were not affected by CCK-8 and GIP together. We conclude that in man, both CCK-8, CCK-33, and GIP moderately stimulate basal and meal related insulin release without any synergistic effects and that the peptides do not inhibit the secretion of glucagon.
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PMID:Effects of cholecystokinin (CCK)-8, CCK-33, and gastric inhibitory polypeptide (GIP) on basal and meal-stimulated pancreatic hormone secretion in man. 168 22

Although it is agreed that autoimmune destruction of pancreatic islets in diabetic BB rats is rapid, reports of endocrine cell content of islets from BB diabetic rats at the time of onset of diabetes vary considerably. Because of the rapid onset of the disease (hours) and the attendant changes in islet morphology and insulin secretion, it was the aim of this study to compare islet beta-cell numbers to other islet endocrine cells as close to the time of onset of hyperglycemia as possible (within 12 h). As it has been reported that hyperglycemia renders the beta cell insensitive to glucose, the early effects of different levels of insulin therapy (well-controlled vs. poorly controlled glycemia) on islet morphology and insulin secretion were examined. When measured within 12 h of onset, insulin content of BB diabetic islets, measured by morphometric analysis or pancreatic extraction, was 60% of insulin content of control islets. Despite significant amounts of insulin remaining in the pancreas, 1-day diabetic rats exhibited fasting hyperglycemia and were glucose intolerant. The insulin response from the isolated perfused pancreas to glucose and the glucose-dependent insulinotropic hormone, gastric inhibitory polypeptide (GIP), was reduced by 95%. Islet content of other endocrine peptides, glucagon, somatostatin, and pancreatic polypeptide, was normal at onset and at 2 weeks post onset. A group of diabetic animals, maintained in a hyperglycemic state for 7 days with low doses of insulin, were compared with a group kept normoglycemic by appropriate insulin therapy. No insulin could be detected in islets of poorly controlled diabetics, while well-controlled animals had 30% of the normal islet insulin content.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Insulin secretion and islet endocrine cell content at onset and during the early stages of diabetes in the BB rat: effect of the level of glycemic control. 178 6

Intrajejunal infusion of hypertonic glucose and hypertonic saline inhibits pentagastrin-stimulated gastric acid secretion in man. This effect is generally ascribed to the hyperosmolality of the solutions. Five volunteers were given 50 g glucose in osmolar concentrations of 2700 mosmol/l and 900 mosmol/l, and five were given 25 g glucose in osmolar concentrations of 2700 mosmol/l and 300 mosmol/l. Control studies with intrajejunal infusion of physiologic saline were performed in all subjects. Median inhibition of gastric acid secretion was 91% after 50 g glucose and 47% after 25 g glucose and was unrelated to the osmolar concentration. These findings suggest that the acid-inhibitory effect of intrajejunally administered glucose is related to the glucose load and not to the osmolar concentration. Plasma responses of intact neurotensin, immunoreactivity, NH2-terminal neurotensin immunoreactivity, enteroglucagon, and gastric inhibitory polypeptide were all related to the amount of glucose given. Glucagon and somatostatin, both of which are potent inhibitors of gastric secretion, were not released by intrajejunally administered glucose.
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PMID:Inhibition of gastric acid secretion by jejunal glucose and its relation to osmolality and glucose load. 196 87


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