Insulin Secreting Cells
Mostrando 13-24 de 70 artigos, teses e dissertações.
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13. Insulin-secreting non-islet cells are resistant to autoimmune destruction.
Transgenic nonobese diabetic mice were created in which insulin expression was targeted to proopiomelanocortin-expressing pituitary cells. Proopiomelanocortin-expressing intermediate lobe pituitary cells efficiently secrete fully processed, mature insulin via a regulated secretory pathway, similar to islet beta cells. However, in contrast to the insulin-prod
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14. Repeated glucose stimulation reveals distinct and lasting secretion patterns of individual rat pancreatic B cells.
To determine whether pancreatic B cells show a constant secretion pattern during repeated stimulations, we have used a sequential hemolytic plaque assay to monitor their individual insulin release during several successive 30-min incubations in the presence of 16.7 mM glucose. We have found that the total B cell secretion did not vary significantly in these
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15. Cloning and functional characterization of a third pituitary adenylate cyclase-activating polypeptide receptor subtype expressed in insulin-secreting cells.
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide belonging to the vasoactive intestinal polypeptide/glucagon/secretin family. It is widely distributed in the body, and a variety of biological actions have been reported. PACAP exerts its biological effects by binding to specific receptors that are coupled to GTP-binding proteins. R
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16. Conserved transducer coupling but different effector linkage upon expression of the myeloid fMet-Leu-Phe receptor in insulin secreting cells.
In neutrophils fMet-Leu-Phe activates phospholipase C via a pertussis toxin sensitive G-protein and induces granule secretion. We have transfected a human cDNA sequence encoding the fMet-Leu-Phe receptor into the insulin secreting cell line RINm5F to study receptor-effector coupling with special regard to secretion. Stable overexpression resulted in membrane
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17. In vivo activity and in vitro specificity of CD4+ Th1 and Th2 cells derived from the spleens of diabetic NOD mice.
CD4+ T cell lines were generated from the spleens of diabetic NOD mice against crude membrane preparations derived from a rat insulinoma. Adoptive transfer of these lines into neonatal mice confirms that overt diabetes is induced by gamma-IFN-secreting Th1 cells, whereas transfer of IL-4-secreting Th2 cells resulted in a nondestructive peri-islet insulitis.
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18. Regulation of insulin mRNA abundance and adenylation: dependence on hormones and matrix substrata.
The insulin mRNA levels of rat insulinoma cell lines increased six- to eightfold, and the cells entered a transient state of growth arrest when they were cultured in serum-free, hormonally defined medium and on an extract of extracellular matrix derived from a basement membrane-secreting tumor line, EHS. Insulinoma cultures in growth arrest responded to gluc
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19. Activity-dependent mobilization of the adhesion molecule polysialic NCAM to the cell surface of neurons and endocrine cells.
The alpha-2,8-linked sialic acid polymer (PSA) on the neural cell adhesion molecule (NCAM) is an important regulator of cell surface interactions. We have examined the translocation of PSA-NCAM to the surface of cultured cortical neurons and insulin secreting beta cells under different conditions of cell activity. Endoneuraminidase N, an enzyme that specific
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20. The Transcriptional Repressor REST Determines the Cell-Specific Expression of the Human MAPK8IP1 Gene Encoding IB1 (JIP-1)
Islet-brain 1 (IB1) is the human and rat homologue of JIP-1, a scaffold protein interacting with the c-Jun amino-terminal kinase (JNK). IB1 expression is mostly restricted to the endocrine pancreas and to the central nervous system. Herein, we explored the transcriptional mechanism responsible for this preferential islet and neuronal expression of IB1. A 731
American Society for Microbiology.
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21. Galanin activates nucleotide-dependent K+ channels in insulin-secreting cells via a pertussis toxin-sensitive G-protein.
The effects of galanin (7-70 nM) on ATP-sensitive K+ channels (KATP channels), membrane potential and the release of insulin have been studied in the insulinoma cell line, RINm5F. Single-channel currents have been recorded from excised outside-out membrane patches as well as intact insulin-secreting cells and it is shown that galanin, added to the outside of
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22. VAMP-2 and cellubrevin are expressed in pancreatic beta-cells and are essential for Ca(2+)-but not for GTP gamma S-induced insulin secretion.
VAMP proteins are important components of the machinery controlling docking and/or fusion of secretory vesicles with their target membrane. We investigated the expression of VAMP proteins in pancreatic beta-cells and their implication in the exocytosis of insulin. cDNA cloning revealed that VAMP-2 and cellubrevin, but not VAMP-1, are expressed in rat pancrea
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23. Vasopressin directly closes ATP-sensitive potassium channels evoking membrane depolarization and an increase in the free intracellular Ca2+ concentration in insulin-secreting cells.
The effects of arginine-vasopressin (AVP) (0.01-1 microM) on membrane potential, [Ca2+]i and ATP-sensitive potassium channels have been studied in the insulin-secreting cell line RINm5F. In whole cells, with an average spontaneous cellular transmembrane potential of -64 +/- 3 mV (n = 33) and an average basal [Ca2+]i of 102 +/- 6 nM (n = 40), AVP evoked: (i)
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24. Attenuation of insulin secretion by insulin-like growth factor 1 is mediated through activation of phosphodiesterase 3B
Both insulin and insulin-like growth factor 1 (IGF-1) are known to reduce glucose-dependent insulin secretion from the β cells of pancreatic islets. In this paper we show that the mechanism by which IGF-1 mediates this effect is in large part through activation of a specific cyclic nucleotide phosphodiesterase, phosphodiesterase 3B (PDE3B). More specificall
The National Academy of Sciences of the USA.