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 chromogranins are acidic proteins present in various endocrine cells and organs. They consist of chromogranin A (CgA), chromogranin B (CgB) and secretogranin II (SgII). In the pancreas, these proteins or their breakdown products are possibly involved in the regulation of pancreatic hormone secretion. The guinea-pig endocrine pancreas was now investigated immunohistochemically for the presence of the chromogranins in five endocrine cell types. CgA is a regular constituent of insulin (B-), pancreatic polypeptide (PP-) and enterochromaffin (EC-) cells. In addition, a minority of somatostatin (D-) cells were immunoreactive for CgA. CgB immunoreactivities were very faint and exclusively observed in B-cells. SgII was found in B- and PP-cells; a faint immunostaining for SgII was also seen in a few glucagon (A-) cells. Typically, the densities of CgA or SgII immunoreactivities varied among the members of a given cell population, e.g. among individual B- or PP-cells. The present findings about the heterogeneities of immunoreactivities for the chromogranins are in line with findings obtained in pancreatic endocrine cells of other species. The true reasons for these heterogeneities are enigmatic. It seems probable, however, that the corresponding immunoreactivities depend on the intracellular processing of the chromogranins which in turn might be related to the metabolic state of endocrine cells. This has to be examined in future by experimental investigations.
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PMID:Immunoreactivities for chromogranin A and B, and secretogranin II in the guinea-pig endocrine pancreas. 198 Sep 16

Chromogranins A and B and secretogranin II have been localized in a wide spectrum of gastroenteropancreatic endocrine/paracrine cells. Chromogranin A immunoreactivity showed the widest distribution and was displayed by glucagon-, PP-, gastrin-, gastrin-CCK-, secretin-immunoreactive cells, the most intense stainings being peculiar of enterochromaffin cells. Chromogranin B immunoreactivity was detected in gastrin- and glucagon cells and in some enterochromaffin cells containing also chromogranin A. Secretogranin II was paired to chromogranin A in glucagon cells of pancreatic islets or occurred alone in glycentin/PP cells of colonic mucosa. Neither of the chromogranins nor secretogranin II have been so far detected in somatostatin-, GIP-, or motilin-immunoreactive cells. Chromogranin A but not chromogranin B or secretogranin II has been detected in the gastric argyrophilic ECL cells.
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PMID:Chromogranins A and B and secretogranin II in hormonally identified endocrine cells of the gut and the pancreas. 322 65

In the endocrine pancreas, chromogranins A and B as well as secretoneurin (a biologically active peptide processed endoproteolytically from secretogranin II) are most intensely expressed in alpha (glucagon) cells. We examined whether the functional status of neoplastic and nonneoplastic human alpha cells is reflected in the expression patterns of chromogranins/secretogranins. Neoplastic alpha cells were analysed immunocytochemically in six functioning glucagonomas and 37 nonfunctioning neuroendocrine tumours (29 with alpha cells) for their immunoreactivity to chromogranin A and B, as well as secretoneurin. There was no difference in the staining intensity for either peptide between glucagonomas and nonfunctioning, alpha cell containing tumours. Nonneoplastic alpha cells from patients with a functioning glucagonoma showed a decreased glucagon immunoreactivity, whereas the expression of chromogranin A (but not chromogranin B and secretoneurin) was as intense as in alpha cells not associated with glucagonoma syndrome. These results suggest that the expression of chromogranins/secretogranins in neoplastic alpha cells of the pancreas may be independently regulated from the cells' functional status. In nonneoplastic alpha cells there seems to be an association between glucagon production and chromogranin B and secretoneurin expression.
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PMID:Expression of chromogranin A and B and secretoneurin immunoreactivity in neoplastic and nonneoplastic pancreatic alpha cells. 795 97

Proglucagon (proG) is processed in a tissue-specific manner to glucagon in the pancreas and to gilcentin, oxyntomodulin, glucagon-like peptide (GLP)-1, and GLP-2 in the intestine. Recombinant vaccinia virus (vv) vectors were used to infect prohormone convertase 1 (PC1) or PC2 into nonendocrine (BHK-proG) cells, which stably express proG. Similarly, endocrine (GH3, AtT-20) cells were coinfected with proG along with PC1 or PC2 alone, or in combination with furin, PACE4, PC5a, or PC5b. Cell extracts were analyzed for various proG-derived peptides by RIA of fractions obtained from HPLC. Upon infection of BHK-proG cells with either vv: furin or vv:PC1, glicentin was produced, while vv: PC2 did not process proG. In GH3 and AtT-20 cells, vv:PC1 produced glicentin, oxyntomodulin, GLP-1(1-37), GLP-1(7-37), and GLP-2. All other enzymes tested produced only glicentin. Interestingly, no enzyme or combination produced glucagon. Coinfection of GH3 cells with vv:PC2 and members of the chromogranin family of peptides, including chromogranin A and B and secretogranin II, as well as the PC2-binding protein 7B2, did not result in processing to glucagon. It is concluded that: 1) PC1 is responsible for the processing of proG to produce the intestinal peptides glicentin, oxyntomodulin, GLP-1(1-37), GLP-1(7-37), and GLP-2, and 2) PC2 processes proG to glicentin but does not produce glucagon, alone or in combination with other enzymes or with known molecular chaperones.
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PMID:Role of prohormone convertases in the tissue-specific processing of proglucagon. 872 80

Manserin is a recently characterized 40-amino acid neuropeptide derived from secretogranin II, a protein belonging to the chromogranin family. Although the physiological roles of manserin have not been elucidated to date, manserin has been shown to distribute in not only the brain but also the endocrine system such as the pituitary and adrenal glands, suggesting its role in the endocrine system. The present study aimed to explore the occurrence and distribution of manserin in the rat pancreas using an immunohistochemical technique with a polyclonal antibody against rat manserin. Immunoreactivity for manserin was readily detected in almost whole islets of Langerhans whereas not at all in the exocrine pancreas. Manserin-expressing cells were not colocalized with the glucagon-secreting cells (alpha cells), whereas they colocalized with insulin-secreting cells (beta cells) and somatostatin-secreting cells (delta cells), although their intracellular distribution was different. These results indicate that manserin, occurring in the endocrine pancreas, may have a potential role in the endocrine system.
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PMID:Manserin, a secretogranin II-derived peptide, distributes in the rat endocrine pancreas colocalized with islet-cell specific manner. 2049 19