Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01350 (gastrin)
 9,683 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was designed to examine and compare the nature of gastrinlike and cholecystokininlike peptides released into the portal and peripheral venous circulation in response to a peptone meal. Six dogs were prepared with portal venous catheters and gastric fistulas. Portal and peripheral venous sera were obtained before and after gastric infusion of a 10% peptone meal. Serum levels of gastrin and cholecystokinin immunoreactive peptides were determined by radioimmunoassay using two distinct peptide region-specific antibody preparations. These separate antibody preparations demonstrated specificity for (a) C-terminal tetradecapeptide gastrin (4-17hG17), heptadecapeptide gastrin (G17), and big gastrin (G34) (gastrin antibody); and (b) all biologically active forms of gastrin and cholecystokinin (gastrin-cholecystokinin antibody). Using the antibody preparation with specificity for gastrin and not cholecystokinin, the mean basal immunoreactive gastrin from portal (8.33 +/- 2.4 fmol/ml, mean +/- SEM) and from peripheral (6.19 +/- 0.9 fmol/ml) venous sera both increased after peptone infusion, with an early peak (2 min in portal and 4 min in peripheral serum) and a second peak at 30 min in both circulations. Measurements using antibodies with specificity for both cholecystokinin and gastrin yielded strikingly different results. The portal venous serum peptide concentration (49 +/- 10 fmol/ml) increased sharply within 30 s after peptone infusion to a single peak at 2 min (139 +/- 37 fmol/ml). The basal peripheral venous serum peptide concentration (43 +/- 8.8 fmol/ml) increased more gradually to a single peak at 8 min (78 +/- 14 fmol/ml). Studies with Sephadex (G-50 superfine) gel chromatography indicated that gastrin released in response to the peptone meal was primarily G17. However, of the peptides released in response to the peptone meal that were recognized by the gastrin-cholecystokinin antibody, greater than 80% were shown to be distinct from gastrin. Gel chromatographic studies demonstrated that peptone meal-stimulated immunoreactive cholecystokinin release consisted of two major peaks, eluting in positions identical to those of intact cholecystokinin (CCK33) and the octapeptide of cholecystokinin (CCK8).
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PMID:Immunochemical characterization of gastrinlike and cholecystokininlike peptides released in dogs in response to a peptone meal. 620 7

Physiologic concentrations of human gastrin I (G17) and a synthetic analog of the carboxy-terminal region of gastrin, pentagastrin, provoked a dose-related release of histamine from human cutaneous mast cells in vitro. The N-terminal tridecapeptide portion of gastrin (G1-13) neither stimulated histamine release nor blocked the action of G17. In vivo correlation studies demonstrated that low concentrations (10(-12)M to 10(-10)M) of G17 or pentagastrin administered intradermally provoked a modest but definite wheal-and-flare response in four out of six normal subjects and a more marked, dose-related response in a patient with mastocytosis. These results indicate that physiologic concentrations of gastrin can stimulate mediator release from human cutaneous mast cells. We propose that this response may be mediated through receptors recognizing the carboxy-terminal region of the gastrin molecule. The possible role of gastrin-induced human mast cell-mediator release should be considered in the assessment of allergic disorders and in experimental models investigating mast cell function.
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PMID:Gastrin induces histamine release from human cutaneous mast cells. 620 35

Antibodies to the peptides (designated cryptic A and B) that flank the G34 region of pig progastrin were used in immunohistochemical studies of the gastrointestinal tract. In elution and restaining experiments, the same cells were revealed by the cryptic peptide antibodies, and by antibodies specific for C-terminus of G17 and N-terminus of G34. The cells reacting with the cryptic peptide antibodies were localized predominantly to antral mucosa. They were found in pig, ferret, dog and cat but not in man, guinea pig, rat or mouse; presumably in the latter species there are amino acid substitutions in the cryptic peptides that influence immunoreactivity with the present antibodies. The results indicate that progastrin production occurs only in G cells in the gut, and that a single population of cells produces all the predicted regions of progastrin.
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PMID:Immunohistochemical localization to pyloric antral G cells of peptides derived from porcine preprogastrin. 620 75

1. The distributions of gastrin- and cholecystokinin-like immunoreactivities in the dog and cat vagus nerves have been studied after nerve section and ligation. 2. In dogs, there was an increase in cholecystokinin-octapeptide-like immunoreactive material on the cranial side of ligatures on the thoracic or cervical vagi. When pairs of ligatures were tied on the cervical vagi there was accumulation proximal, and a slight decrease distal to, the upper ligature. There was also a modest increase distal to the lower ligature. 3. In cats, section of the vagus above the nodose ganglion, and hence degeneration of the efferent fibres, did not prevent increases in cholecystokinin-octapeptide-like immunoreactivity on the cranial side of ligatures which were later tied below the ganglion. Removal of the superior cervical ganglion had no effect on the accumulation of immunoreactive material above the ligatures. Section of the vagus below the nodose ganglion, and hence degeneration of both afferent and efferent fibres, abolished the accumulation on the cranial side of ligatures which were later tied below the section. Cholecystokinin-octapeptide-like material is therefore localized to afferent fibres with cell bodies in the nodose ganglion. 4. Immunoreactive forms were characterized by gel filtration and ion exchange chromatography, and the use of region-specific antisera. In all cats, and all but one dog, a molecule with the properties of sulphated cholecystokinin octapeptide was found to predominate. In some cats (30%) and dogs (26%) a molecule with the properties of heptadecapeptide gastrin (G17) was identified; concentrations of G17 were generally low compared with cholecystokinin octapeptide. In three dogs (20%) there was an accumulation of heptadecapeptide gastrin above the ligatures. 5. Axonal transport of cholecystokinin octapeptide in the vagus is consistent with a neuro-regulatory role for this peptide. However, the functional significance of its localization in afferent fibres, and transport towards the periphery, remains to be determined.
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PMID:Transport of cholecystokinin-octapeptide-like immunoreactivity toward the gut in afferent vagal fibres in cat and dog. 627 37

A newly synthesized human big gastrin (G34) that was prepared according to the revised structure and that contained less than 3% oxidized methionine residues was compared with synthetic human little gastrin (G17) for acid-stimulating activity and clearance in human subjects. Prolonged infusions of each type of gastrin revealed that the time required to approach stable plasma concentrations was much longer for G34 than for G17. The time course of plasma gastrin concentration could be described by one-compartment models with half-lives of 44 min for G34 and 8 min for G17. After rapid intravenous infusion, G34 produced a much larger total acid response than did an equimolar dose of G17, and the responses were directly proportional to the integrated plasma gastrin increments. During the third hour of prolonged intravenous infusions of G34 and G17, the exogenous dosage of G34 required to produce the same blood concentration of gastrin was only one-fourth that of G17. Equivalent blood concentrations of G34 and G17 were associated with similar rates of acid secretion. These results suggest that G34 is more potent than has been thought, that it has an activity similar to that of G17 and that it must not be ignored in estimating total acid-stimulating activity of circulating gastrins. The measurement of total carboxyl-terminal immunoreactive gastrin can produce a good estimate of total acid-stimulating activity.
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PMID:Similar acid stimulatory potencies of synthetic human big and little gastrins in man. 671 38

In order to study some of the molecular events during the hepatic passage of gastrin, we perfused sulfated natural porcine gastrin (G17 II) through isolated pig livers. The disappearance half time of G17 II was about 20-30 min when the starting gastrin concentrations were greater than 100 pM; lower concentrations were reduced with half times of 40-100 min. Synthetic human leu-32 (G34) was not eliminated. The use of region-specific antibodies to gastrin indicated that degradation was more effective at the N-terminus of gastrin. Whereas Sephadex chromatography revealed no change of the molecular size, SDS-polyacrylamide gel electrophoresis showed the presence of smaller immunoreactive fragments of gastrin in addition to immunoreactive fragments of gastrin of the heptadecapeptide size. These findings indicate that the isolated porcine liver degrades porcine G17 to smaller fragments.
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PMID:Elimination of porcine heptadecapeptide gastrin (G17) and human leu big gastrin (G34) by the perfused pig liver. 674 10

Parietal cell antibodies (PCA) are found in up to 90% of sera from pernicious anaemia patients but it is often stated that they could represent an epiphenomenon without being directly responsible for the achlorhydria. In the present studies a direct effect of these antibodies on the secretory function of gastric acid-secreting cells has been demonstrated in two different experimental systems. In one set of experiments IgGs containing PCA activity were shown to inhibit acid secretion specifically in the living gastric mucosa of the bull frog suspended as a diaphragm between two chambers. The other system demonstrated their inhibition of carbonic anhydrase activity in a cytochemical bioassay for human G17-gastrin, suggesting a blocking effect on the gastrin receptors in the canalicular microvilli or the cell membrane. These experiments suggest a direct pathogenic role for PCA in autoimmune fundal gastritis and in pernicious anaemia.
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PMID:Inhibition of parietal cell function by human gammaglobulin containing gastric parietal cell antibodies. 677 2

We have studied the relationships between the main molecular forms of gastrin (G17 and G34) in the serum, antral and duodenal mucosa of duodenal (DU) and gastric (GU) ulcer patients. Fasting serum G17 was similar in both DU and GU (about 6 pmol/l) and in both groups increased about three-fold with feeding. In contrast, basal serum G34 was significantly higher in GU (29 pmol/l) than in DU (12 pmol/l) and the peak post prandial increase over basal of G34 was also higher in GU (57 pmol/l) compared with DU (10 pmol/l). In sharp contrast, in the same groups of DU and GU patients mean total antral gastrin concentrations were similar (about 12 nmol/g), and in both groups 95% of antral gastrin was G17, most of the remainder being G34. In both groups total duodenal gastrin concentrations were about 20% those in antral mucosa and about 70% of duodenal gastrin was attributable to G34. The higher serum G34 in GU could therefore be explained by increased secretion of duodenal gastrin, but further work is needed to examine whether there might also be preferential secretion of antral G34 in GU, or a difference in the metabolism (or volume of distribution) of gastrin variants in GU and DU.
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PMID:Molecular forms of gastrin in peptic ulcer: comparison of serum and tissue concentrations of G17 and G34 in gastric and duodenal ulcer subjects. 678 21

A cytochemical section bioassay has been used to assess the carbonic anhydrase activity, induced by the gastrin peptides G13, G17 and G34 (concentration 5.0-0.005 pg/ml), in guinea pig parietal cells. When the mean integrated density of the induced response x 100, was plotted against the concentration of the gastrin peptide used, a graded dose response and a positive linear correlation was found for G13 and G17. These responses were similar. G34 did not produce a linear dose response in the concentration range 5.0-0.005 pg/ml, but a higher overall carbonic anhydrase activity was observed than with G13 and G17.
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PMID:The biological activity of different gastrin peptides assessed using a cytochemical section bioassay. 679 24

Seven Sprague-Dawley rats (404-440 g) underwent a 90% jejuno-ileal bypass (JIB); the functional loop consisted of 1/3 ileum and 2/3 jejunum with the bypassed loop being anastomosed to the ascending colon. Seven control rats were sham-operated. After 35 days, the rats were fasted 18 hours and venous blood was collected. Immunoreactivity of gastrin, measured with an antibody binding equally to G17 and G34, was higher in the plasma of the JIB (256 +/- 55 SEM pg/ml) than control (85 +/- 9 pg/ml) rats. This agrees with recent human studies but is in conflict with results in less mature rats. VIP levels were not significantly different. Glucagon-like immunoreactivity measured with antibodies specific for the C- and N-terminal regions of the hormone, respectively, were also higher in the JIB (510 +/- 40 and 129 +/- 15 pg/ml) rats.
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PMID:Circulating immunoreactivities of gastrin, glucagon and VIP after jejuno-ileal bypass. 707 93


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