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 electron microscopic localization of insulin, glucagon, somatostatin, and pancreatic polypeptide (PP) in the pancreas of the iguanid lizard, Anolis carolinensis was studied by the unlabeled antibody peroxidase-antiperoxidase immunocytochemical technique. Insulin, glucagon, and somatostatin were localized absolutely to those cells previously identified on the basis of the characteristics of their secretory granules as being beta cells, alpha cells, and D cells, respectively. The secretory granule cores of the PP-containing cells appeared to be ellipsoidal with a semi-major axis of 450 nm and a semi-minor axis of 365 nm. This previously unidentified cell type is named the F cell, in keeping with the localization of PP to the original F cell of the canine pancreas. Without immunocytochemical staining, the qualitative ultrastructural characteristics of the F cell secretory granules were inadequate to permit identification of the F cell, especially with regard to the D cell.
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PMID:Four hormones in the pancreas of the lizard, Anolis carolinensis. 611 34

Insulin, glucagon, somatostatin, and pancreatic polypeptide (PP) were localized in the pancreas of the common garter snake, Thamnophis sirtalis, by light and transmission electron microscopic (TEM) immunocytochemistry. Colloidal gold-protein A was used for TEM localization and the peroxidase--antiperoxidase complex technique was used for light microscopy. The glucagon-containing A cells and the insulin-positive B cells were the most numerous cell types. The somatostatin-containing D cells made up about 15% of the endocrine cells. PP-positive F cells were a minor cell type. The only topographic arrangement of the cells within the endocrine-rich areas that was apparent was the peripheral localization of the D and F cells. Cells of a specific cell type were sometimes grouped together. At the electron microscopic (EM) level, the gold particles (indicating the presence of hormone) were localized nearly exclusively over the secretory granules of the reactive cells. The alpha-granules were the largest found and were predominantly electron dense with a moderately electron-dense periphery. PP-containing granules were the smallest. The somatostatin-reactive delta-granules were round and moderately electron opaque. The beta-granules were heterogeneous in appearance. The morphognomy of the secretory granules of the major endocrine cell types is qualitatively similar to that of mammals. Whether or not the quantitative and/or associative differences contribute to the marked metabolic differences between reptiles and mammals, remains to be determined.
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PMID:Immunocytochemical localization of four hormones in the pancreas of the garter snake, Thamnophis sirtalis. 614 66

A highly sensitive immunoenzymatic technic is presented. The method involves three sequential steps: (1) primary antibody, (2) biotin-labeled secondary antibody, and (3) avidin-biotin-peroxidase complex. Avidin, an egg white protein, has four binding sites for the low-molecular-weight vitamin biotin. Many moieties of biotin can be coupled to the peroxidase molecule. Thus, since a relatively large amount of avidin is incubated with biotin-labeled peroxidase, avidin serves as a link between biotin-peroxidase molecules; in turn, biotin-peroxidase serves as a link between avidin molecules. Consequently, this large lattice-like complex with biotin-binding capability can be attracted to the sites of biotin-labeled antibody, producing a superior staining sensitivity. Several commercially available radioimmunoassay antibodies (e.g., antiglucagon, prolactin, gastrin, growth hormone, and thyroid-stimulating hormone antibodies) were tested for immunohistochemical staining. The unlabeled antibody peroxidase-antiperoxidase method fails to stain gastrin or thyroid-stimulating secretory cells when using these antibodies, and a relatively high antibody concentration is required to produce a positive reaction for glucagon, prolactin, and growth hormone. In contrast, the avidin-biotin-peroxidase complex method successfully demonstrates polypeptide hormones even when antibodies are diluted 20 to 40 times.
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PMID:A comparative study of the peroxidase-antiperoxidase method and an avidin-biotin complex method for studying polypeptide hormones with radioimmunoassay antibodies. 616 37

Paired indirect immunoenzyme staining based on primary antisera from the same species was performed sequentially without intermediate antibody elution. The first antigen was labelled brown by an immunoperoxidase procedure (either the two-stage indirect method, the unlabelled antibody peroxidase-antiperoxidase method, or the avidin-biotin bridge method using diaminobenzidine (DAB) and hydrogen peroxide as the substrates. The second antigen was labelled blue by applying a two-stage indirect immuno-alkaline phosphatase procedure using naphthol AS phosphate and Fast Blue BB salt as the substrate. In this way, polyclonal mucosal immunocytes were revealed in distinctly contrasting colours when stained for kappa and lambda light chains. Glucagon and somatostatin (D) cells in human pancreatic islets, and gastrin and D cells in human gastric antral glands, were likewise clearly differentiated. Conversely, a mixed colour appeared in some immunocytes after staining for alpha and kappa chains. However, unbalanced colour mixing was sometimes difficult to interpret, and additional experiments demonstrated that unwanted interactions could take place between the two sequences of reagents if the density of the DAB deposits was insufficient. These pitfalls were incompatible with unequivocal double staining in the same cell. Nevertheless, paired staining could be conveniently applied with the described procedures when prior knowledge had established that the antigens in question were located in separate cells.
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PMID:Paired indirect immunoenzyme staining with primary antibodies from the same species. Application of horseradish peroxidase and alkaline phosphatase as sequential labels. 620 74

When glucagon is iodinated by the chloramine-T method, the Met27 residue is oxidized. This is not the case when the iodination is performed by the lactoperoxidase method. The two preparations can be purified to the same specific activity using QAE-Sephadex A-25 ion exchange chromatography. Receptor-binding studies in isolated rat adipocytes or hepatocytes revealed that the oxidized from possessed an average-binding affinity which is only about two thirds of that of the non-oxidized form. The reduced affinity of the oxidized tracer cannot be explained by an increased rate of dissociation.
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PMID:The effect of oxidation of the Met27 residue of [125I]monoiodoglucagon on receptor-binding affinity. 627 59

Nineteen spontaneous pancreatic islet cell tumors were studied in 26-month-old control Fischer 344 rats. Seventeen of 19 (89%) tumors demonstrated insulin reactivity using peroxidase-antiperoxidase immunocytochemistry. None of ten tumors had positive glucagon immunoreactivity. Immunocytochemical and ultrastructural observations suggested that spontaneous occurring islet cell tumors of F344 rats were composed exclusively of beta cells.
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PMID:Immunocytochemical demonstration of insulin in spontaneous pancreatic islet cell tumors of Fischer rats. 630 77

Glucagon-like peptides in the central nervous system (CNS) of man with the immunofluorescence and the peroxidase-antiperoxidase method were studied. It has been found that there are immunoreactive glucagon cells present in the hypothalamus hippocampus, amygdaloid nuclei cerebral cortex, and medulla oblongata region. The findings confirm earlier investigations from this laboratory performed along this line.
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PMID:Glucagon-like peptides in the CNS of man: localization and possible functional importance. 654 47

Immunochemical and immunocytochemical techniques have been used to identify and characterize glucagon-related peptides of the rat central nervous system. These peptides show immunoreactivity with antiglucagon sera directed towards the central portion of the hormone, but not with antisera specific for the free COOH terminus of glucagon. Highest concentrations were found in hypothalamus (6.1 +/- 1.6 ng/g wet weight) although lower amounts (approximately 2 ng/g) were found in cortex, thalamus, cerebellum, and brain stem. Gel filtration of brain extracts revealed at least two immunoreactive forms, which have molecular weights of about 12,000 and 8000. Both peptides had radioimmunoassay dilution curves parallel to the curve for glucagon and both had identical counterparts in extracts of rat intestine. Digestion of the brain and intestinal peptides with trypsin plus carboxypeptidase B released the immunoreactive COOH-terminal tryptic fragment of pancreatic glucagon from these larger forms. Immunocytochemical studies using antiglucagon serum and peroxidase-antiperoxidase staining identified glucagon-like material in neuronal cell bodie and processes in the magnocellular portion of the paraventricular nucleus, as well as in scattered cells in the supraoptic nucleus and in fibers in the median eminence. These results suggest that glucagon-containing peptides that have undergone the intestinal type of posttranslational modification are present in neuronal cells of the rat hypothalamus.
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PMID:Identification and localization of glucagon-related peptides in rat brain. 693 48

Isolated rat pancreatic islet extracts were submitted to reverse phase high pressure chromatography (HPLC) and assayed for thyrotrophin releasing factor (TRF), glucagon and insulin in radioimmunoassays (RIA). Our anti-TRF serum was prepared by immunizing rabbits with TRF conjugated to bovine thyroglobulin (bTG) by bisdiazobenzidine. Anti-glucagon and antiinsulin were from a commercial source (Novo, Denmark). The concentrations of TRF, glucagon and insulin were 0.05 +/- 0.02, 0.06 +/- 0.02 and 1.0 +/- 0.2 pmol/islet, respectively. Formalin-fixed pancreatic sections were stained for TRF, glucagon and insulin by peroxidase, antiperoxidase (PAP) complex method. When the adjacent sections were stained for glucagon or insulin, it was observed that TRF and glucagon-specific peroxidase reactions were confined to the marginal islet cells, but insulin reactions to the central cells. The TRF-specific peroxidase reaction was clearly reduced when the anti-TRF serum was unchanged when the antiserum was pre-incubated with synthetic TRF. The present HPLC results suggest that the islets contained TRF. Immunocytochemical studies show that the TRF-immunoreactive material, either synthesized or bound, is localized in the marginal islet cells.
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PMID:Presence of TRF immunoreactivity in marginal islet cells in rat pancreas. 702 Mar 18

The digestive tract of the cephalochordate Branchiostoma lanceolatum was investigated with regard to occurrence and distribution of endocrine cells. By the use of the peroxidase-antiperoxidase (PAP) technique, cells in the gut epithelium reacting with antisera against 8 different mammalian polypeptide hormones were localized. Positive reactions were obtained with antisera against the four mammalian islet hormones (insulin, glucagon, pancreatic polypeptide, somatostatin) and against secretin, vasoactive intestinal polypeptide, pentagastrin and neurotensin. No immunoreactivity was found with antisera members of the lipotropin family (ACTH, met-enkephalin, alpha-endorphin), against big-gastrin, cholecystokinin, substance P and motilin. The exact mapping of the different polypeptide immunoreactive cells throughout the digestive tract of Branchiostoma lanceolatum is presented.
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PMID:Immunohistochemical localization of polypeptide hormones in endocrine cells of the digestive tract of Branchiostoma lanceolatum. 702 87


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