Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The C-terminal region-sepcific anti-glucagon sera were raised in rabbits using as immunogen, and conjugate of BSA and a C-terminal fragment of pancreatic glucagon. The hapten was prepared by trypsin digestion of the glucagon, which was proved to be a 1:3 mixture of glucagon (18--29) and (19--29). Six rabbits were immunized by subcutaneous injection of an emulsion of the conjugate with complete Freund's adjuvant and five of the rabbits produced antibodies to the glucagon (GC-1, GC-2, GC-3, GC-5 and GC-6). For comparison, rabbit antisera were also produced against glucagon polymer (GA-10) and syrupy glucagon fibrils (PGA-2). All these antisera as well as the pancreatic glucagon-specific antiserum 30 K were characterized with dog gut-extract (gut-GLI) and glucagon-related peptide fragments in the radioimmunoassay systems. The assay systems utilized 125 I-monosubstituted pancreatic glucagon as tracer and human mono-component glucagon as standard. All sera of the GC-series crossreacted with the dog gut-extract very weakly and antisera GC-5 and GC-6 exhibited the lowest crossreactivities with the extract, which were shown to be as low as that of 30k. Characterization of the antiserum GC-5 with purified glucagon related fragments indicated that the major antigenic determinant located exactly in the C-terminal region of glucagon. The present results clearly showed high efficiency of the use of the glucagon C-terminal fragment as hepatenic immunogen in obtaining the C-terminal region-specific, i.e., pancreatic glucagon-specific antisera.
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PMID:Production of anti-glucagon sera with a C-terminal fragment of pancreatic glucagon. 8 40

"Gastric inhibitory peptide" or "glucose-dependent insulin-releasing peptide" (GIP) is a member of the gut hormone family. Its physiological action is thought to be related to its insulinotrophic effect. The occurrence and distribution of GIP was studied by immunohistochemistry. In all species examined including man, GIP immunoreactivity was found to reside in the glucagon cells of the pancrease and gut. Three pancreatic glucagonomas were found to contain numerous cells displaying GIP and glucagon immunoreactivity. The GIP antiserum used did not cross react with either pancreatic-type or gut-type glucagon (GLI).
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PMID:Is GIP a glucagon cell constituent? 10 36

Five patients with mild maturity-onset diabetes were given 250 ml of a 20% glucose solution by intraduodenal infusion and eight other patients similarly received an amino acid solution in a dose of 0.5 g amino acids per kg body weight. The pancreatic and gut glucagon-like immunoreactivity (pancreatic GLI and gut GLI) in plasma were measured before and after the application of the two stimuli. Each person was tested twice; the first (control) test was followed by a second test after three days of treatment with phenformin 150 mg daily, plus the same 150 mg dose taken 60 min before the intubation. The plasma pancreatic GLI increased slightly during both infusions, but was not affected by phenformin. Intraduodenal infusion of both glucose and the amino acid solution induced a greater rise in plasma gut GLI. After treatment with phenformin, the fasting plasma gut GLI was higher than the control value in eleven of thirteen patients. In most cases higher gut GLI plasma levels were also found after duodenal administration of glucose and amino acids. These data furnish further evidence of the local action of antidiabetic biguanides on the intestinal wall, including its hormonal activity. The hypothesis is advanced that the phenformin-induced increase in gut GLI secretion may bring about competition of the latter with pancreatic glucagon for receptors in liver cell membranes, reducing the effect of glucagon on the liver, and thus contributing to a decrease in glycaemia.
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PMID:The effect of phenformin upon the plasma pancreatic and gut glucagon-like immunoreactivity in diabetics. 16 7

Glucose, insulin (IRI), pancreatic (IRG) and total (GLI) immunoreactive glucagon were measured in the serum of normal hamsters and of hamsters with an insulin- and glucagon-secreting, transplantable insuloma. The tumor-bearing animals were hypoglycemic, hyperinsulinemic and hyperglucagonemic. The pancreatic islets of tumor-bearing animals secreted less glucagon and insulin in response to arginine or to changes in the glucose concentration of the medium, than did the islets of control hamsters. In addition, the introduction of glucose into the gastro-intestinal tract, which caused a significant rise in the serum GLI concentration of normal hamsters, failed to do so in the tumor-bearing animals. The results suggest that the high levels of serum glucagon and insulin induced by the tumor, suppressed IRI, IRG and GLI secretion in these animals.
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PMID:Secretion of immunoreactive insulin and glucagon in hamsters bearing a transplantable insuloma. 19 57

Three major lipolytic factors, termed peaks 1, 2 and 3, according to their elution sequence from Biogel P6 columns, have been identified in duck intestinal extracts. The small molecular weight peaks 2 and 3, were even more lipolytically potent on chick adipocytes than pancreatic glucagon; peak 1, called gut GLI, because of its cross-reactivity in a radioimmunoassay for glucagon, modified the lipolytic activity of peak 2 and pancreatic glucagon. It did so by modifying their capacity to stimulate cyclic AMP production. Peaks 2 and 3 exert their lipolytic effects via different intermediary pathways: only peak 2 induced the formation of cyclic AMP. Insulin in birds is devoid of any antilipolytic activity; this fundamental role may be assumed by gut GLI.
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PMID:Antilipolytic nature of gut GLI, and mode of action of two highly potent intestinal lipolytic species in birds. 21 10

Porcine glucagon was modified at methionine-27 by methylation or oxidation. Antisera against the glucagon derivatives were obtained. One of these antisera showed a high affinity for glucagon, with no cross-reactivity with gut-GLI 1. Biological activities of these derivatives were assessed on rat hepatocytes. Both derivatives had the same maximal glucose-mobilising activity as native glucagon, but a decrease potency, suggesting a crucial role of methionine in the binding of glucagon to its hepatic receptor.
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PMID:Immunogenicity and bioactivity of glucagon, modified at methionine-27. 22 76

From the mucosa of the gastrointestinal tract a number of peptides can be extracted, which are glucagon-like in their behavior towards antisera raised against the pancreatic hormone. The biochemistry and physiology of these peptides are critically reviewed. Although important advances have been made, facilitated by improved praparative and analytical techniques, many problems remain unresolved. It is, however, now well established that a peptide, which is indistinguishable from true, pancreatic glucagon (NW 3,485) is found in extrapancreatic gastrointestinal tissue from all species investigated. While abundant in dogs, especially in the gastric mucosa, much less is found in extra-pancreatic tissues of man and pig. Results from studies in dogs are therefore not necessarily relevant to other species. Human and porcine gut, however, contain other glucagon-like peptides (gut-type glucagon, enteroglucagon, gut GLI), one of which resembles true glucagon (MW 3,485) in its biological activity, but a definite physiological role for these peptides has not yet been established. The recent isolation and purification of one of the latter peptides undoubtedly will facilitate greatly future research in this field.
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PMID:Extrapancreatic glucagons. 34 23

A 45-year-old man was operated for surgical treatment of a long-standing peptic ulcer disease and upon inspection of the pancreas for suspected Zollinger-Ellison syndrome, tumor nodules were found in this organ. The tumor tissue examined by immunofluorescence showed specific staining only after incubation with anti-pancreatic polypeptide. Negative results were obtained with antisera directed against insulin, pancreatic glucagon, somatostatin, GLI, VIP, secretin, and gastrin. Examination of the tissue by electron microscopy revealed a homogeneous population of small granule-containing cells. This case, therefore, illustrates a tumor composed of one single hormone-producing cell type and allows definition of the ultrastructural features of human pancreatic polypeptide-containing cells.
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PMID:Human islet cell tumor storing pancreatic polypeptide: a light and electron microscopic study. 37 22

The cellular and subcellular localization of one of the gut glucagon-like immunoreactants (GLI-1 or glicentin) and the relative distribution of glicentin- and glucagon-containing cells were investigated by immunocytochemistry. By immunofluorescence, the antiglicentin serum, which does not react with glucagon, revealed positive cells in the islets of Langerhans and in the gut mucosa, particularly in the terminal ileum and colon. In the intestinal mucosa, it was proven ultrastructurally that the glicentin immunoreactive cells correspond to the L cell and that the secretory granules represent the storage compartment of the immunoreactive material. In pancreatic islets, consecutive semithin sections treated with antiglicentin and specific antiglucagon sera showed that the same A cell population reacted with both sera, while immunoperoxidase staining on thin sections revealed that the immunoreactive material was confined to the secretory granules. The same results were obtained on dog oxyntic mucosa, where the glicentin- and glucagon-containing cells were identified as the gastric A cell. The immunocytochemical demonstration of a common glicentin-like material in the A and L cells together with the known presence of a common immunoreactant in glicentin and glucagon strongly support the idea that the A and L cells are ontogenetically related and synthesize their secretory product via a glicentin-like precursor which, by specific cleavage, could yield glucagon and gut glucagon-like immunoreactants.
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PMID:Glicentin immunoreactive cells: their relationship to glucagon-producing cells. 37 54

The composition, half life and hyperglycemic action of the porcine gastrointestinal glucagon-like immunoreactive materials were examined. Glucagon immunoreactivity (GI) measured using specific antiglucagon serum was more abundunt in the extract from the gastric fundus than in the one from the small intestine. When the extract from the gastric fundus was injected in dogs, the half life (T1/2) of total glucagon-like immunoreactivity (total GLI) measured using nonspecific antiglucagon serum was 9.5 +/- 1.1 min (mean +/- SEM), which was longer than that of crystalline pancreatic glucagon, 3.4 +/- 0.2 min, but shorter than that of the extract from the small intestine, 15.9 +/- 1.3 min. On the other hand, T1/2 for GI from the gastric fundus was 5.1 +/- 0.9 min, which was not significantly different from that of crystalline pancreatic glucagon. Blood sugar levels were significantly increased from the basal by 25 +/- 4 mg/100 ml at 10 min and 19 +/- 4 mg/100 ml at 15 min following an injection of the extract from the gastric fundus, but such a change in blood sugar levels was not demonstrated when the extract from the small intestine was injected. These results suggest that GI of the gastric fundus is close to pancreatic glucagon in respect of its metabolism and hyperglycemic activity.
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PMID:Half life of gastrointestinal glucagon-like immunoreactive materials. 43 1


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