rdf:type |
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lifeskim:mentions |
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pubmed:issue |
1
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pubmed:dateCreated |
2001-5-25
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pubmed:abstractText |
Somatostatin hyperpolarized rat pancreatic alpha-cells and inhibited spontaneous electrical activity by activating a low-conductance K+ channel (0.9 pS with physiological ionic gradients). This channel was insensitive to tolbutamide (a blocker of ATP-sensitive K+ channels) and apamin (an inhibitor of small-conductance Ca(2+)-activated K+ channels). Channel activation was prevented by pre-treating the cells with pertussis toxin, indicating the involvement of G-proteins. A direct interaction between an inhibitory G-protein and the somatostatin-activated K+ channel is suggested by the finding that intracellular application of guanosine 5'-O-(3-thiotriphosphate) (GTP gamma-S) and the G beta gamma subunit of G-proteins resulted in a transient stimulation of the current. Activation of the K+ current by somatostatin was inhibited by intracellular dialysis with specific antibodies to Gi1/2 and was not seen in cells treated with antisense oligonucleotides against G-proteins of the subtype Gi2. We conclude that somatostatin suppresses alpha-cell electrical activity by a Gi2-protein-dependent mechanism, which culminates in the activation of a sulphonylurea- and apamin-insensitive low-conductance K+ channel.
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Antibodies,
http://linkedlifedata.com/resource/pubmed/chemical/Apamin,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/GTP-Binding Protein alpha...,
http://linkedlifedata.com/resource/pubmed/chemical/Guanosine 5'-O-(3-Thiotriphosphate),
http://linkedlifedata.com/resource/pubmed/chemical/Pertussis Toxin,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channel Blockers,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Somatostatin,
http://linkedlifedata.com/resource/pubmed/chemical/Somatostatin,
http://linkedlifedata.com/resource/pubmed/chemical/Tolbutamide,
http://linkedlifedata.com/resource/pubmed/chemical/Virulence Factors, Bordetella
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pubmed:status |
MEDLINE
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pubmed:month |
Apr
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pubmed:issn |
0031-6768
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
442
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
19-26
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pubmed:dateRevised |
2009-11-19
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pubmed:meshHeading |
pubmed-meshheading:11374064-Animals,
pubmed-meshheading:11374064-Antibodies,
pubmed-meshheading:11374064-Apamin,
pubmed-meshheading:11374064-Calcium,
pubmed-meshheading:11374064-Dialysis,
pubmed-meshheading:11374064-Electric Conductivity,
pubmed-meshheading:11374064-GTP-Binding Protein alpha Subunits, Gi-Go,
pubmed-meshheading:11374064-Guanosine 5'-O-(3-Thiotriphosphate),
pubmed-meshheading:11374064-Islets of Langerhans,
pubmed-meshheading:11374064-Male,
pubmed-meshheading:11374064-Pertussis Toxin,
pubmed-meshheading:11374064-Potassium Channel Blockers,
pubmed-meshheading:11374064-Potassium Channels,
pubmed-meshheading:11374064-Rats,
pubmed-meshheading:11374064-Rats, Inbred Lew,
pubmed-meshheading:11374064-Receptors, Somatostatin,
pubmed-meshheading:11374064-Somatostatin,
pubmed-meshheading:11374064-Tolbutamide,
pubmed-meshheading:11374064-Virulence Factors, Bordetella
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pubmed:year |
2001
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pubmed:articleTitle |
Gi2 proteins couple somatostatin receptors to low-conductance K+ channels in rat pancreatic alpha-cells.
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pubmed:affiliation |
Novo Nordisk A/S, Novo Alle, 2880 Bagsvaerd, Denmark. jesper_gromada@lilly.com
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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