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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
1
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pubmed:dateCreated |
1993-2-5
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pubmed:abstractText |
Using the glucose-responsive hamster beta-cell line (hamster insulin tumor cells), we examined the cellular mechanisms by which gastric inhibitory polypeptide (GIP) and glucagon-like peptide I(7-37) (GLP-I) potentiate glucose-stimulated insulin secretion. Glucose alone increased insulin secretion and increased the free cytosolic calcium levels ([Ca2+]i) without altering cAMP content. When added to glucose-stimulated cells, GIP and GLP-I increased cAMP levels and further increased insulin secretion. At 4 mM but not 0.4 mM glucose, both peptides triggered a dose-dependent rise in [Ca2+]i with ED50s of 0.4 and 0.2 nM for GIP and GLP-I, respectively. The increase in [Ca2+]i was blocked by either chelation of extracellular Ca2+ with EGTA or nimodipine, the voltage-dependent Ca2+ channel blocker. Nimodipine also inhibited the potentiation of glucose-stimulated insulin secretion by GIP and GLP-I without inhibition of the stimulatory effect of these two peptides on cAMP accumulation. Neither peptide altered phosphoinositide metabolism, further underlining that the mobilization of intracellular Ca2+ from endoplasmic reticulum is not involved in the GIP and GLP-I signal transduction pathways. This study establishes that GIP and GLP-I potentiate glucose-stimulated insulin secretion by increasing extracellular Ca2+ influx through voltage-dependent Ca2+ channels.
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pubmed:grant |
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
AIM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP,
http://linkedlifedata.com/resource/pubmed/chemical/Egtazic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Gastric Inhibitory Polypeptide,
http://linkedlifedata.com/resource/pubmed/chemical/Glucagon,
http://linkedlifedata.com/resource/pubmed/chemical/Glucagon-Like Peptide 1,
http://linkedlifedata.com/resource/pubmed/chemical/Glucagon-Like Peptides,
http://linkedlifedata.com/resource/pubmed/chemical/Insulin,
http://linkedlifedata.com/resource/pubmed/chemical/Nimodipine,
http://linkedlifedata.com/resource/pubmed/chemical/Peptide Fragments,
http://linkedlifedata.com/resource/pubmed/chemical/Peptides,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylinositols,
http://linkedlifedata.com/resource/pubmed/chemical/glucagon-like peptide 1 (7-37)
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pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0013-7227
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
132
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
94-100
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pubmed:dateRevised |
2011-11-17
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pubmed:meshHeading |
pubmed-meshheading:8380389-Animals,
pubmed-meshheading:8380389-Calcium,
pubmed-meshheading:8380389-Cricetinae,
pubmed-meshheading:8380389-Cyclic AMP,
pubmed-meshheading:8380389-Cytosol,
pubmed-meshheading:8380389-Egtazic Acid,
pubmed-meshheading:8380389-Gastric Inhibitory Polypeptide,
pubmed-meshheading:8380389-Glucagon,
pubmed-meshheading:8380389-Glucagon-Like Peptide 1,
pubmed-meshheading:8380389-Glucagon-Like Peptides,
pubmed-meshheading:8380389-Insulin,
pubmed-meshheading:8380389-Islets of Langerhans,
pubmed-meshheading:8380389-Nimodipine,
pubmed-meshheading:8380389-Peptide Fragments,
pubmed-meshheading:8380389-Peptides,
pubmed-meshheading:8380389-Phosphatidylinositols,
pubmed-meshheading:8380389-Signal Transduction,
pubmed-meshheading:8380389-Tumor Cells, Cultured
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pubmed:year |
1993
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pubmed:articleTitle |
The role of the free cytosolic calcium level in beta-cell signal transduction by gastric inhibitory polypeptide and glucagon-like peptide I(7-37).
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pubmed:affiliation |
Division of Endocrinology, Diabetes, Metabolism, and Molecular Medicine, New England Medical Center, Boston, Massachusetts 02111.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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