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rdf:type |
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lifeskim:mentions |
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pubmed:dateCreated |
1997-3-14
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pubmed:abstractText |
1. The effects of GTP and Ca2+ on secretion from single pancreatic beta-cells were studied using capacitance measurements as an indicator of exocytosis. 2. GTP or GTP gamma S produced a concentration-dependent increase in cell capacitance in the absence of intracellular calcium. There was no effect of cyclic AMP or BAPTA an GTP-induced secretion. 3. In the absence of GTP, the relationship between intracellular calcium concentration and the maximum rate of secretion was fitted by the Hill equation with a slope factor of 2.5 and half-maximal activation at 1.6 microM intracellular Ca2+. Similar values were obtained in the presence of GTP gamma S, suggesting GTP does not alter the sensitivity of the secretory machinery to Ca2+. 4. GDP beta S alone had no effect on cell capacitance but caused a dose-dependent inhibition of exocytosis induced by infusion of either GTP gamma S or Ca2+, suggesting both stimuli involve G-protein activation. GDP beta S was without effect on exocytosis evoked by depolarization-mediated Ca2+ entry. 5. The time course of exocytosis following rapid elevation of GTP gamma S by photolysis of a caged precursor was dependent on the intracellular Ca2+ and cyclic AMP concentrations. 6. Our results are interpreted in terms of a model in which the secretory pathways stimulated by Ca2+ and GTP contain both common and separate parts.
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pubmed:grant |
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-1719424,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-1751542,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-2109965,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-2119172,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-2675833,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-2687638,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-3031036,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-3315034,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-4577291,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-6959149,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-7684514,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-7692389,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-7796801,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-7828595,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-8016866,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-8145165,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-8187872,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-8338512,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-8338664,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-8343109,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-8427700,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8910213-8814605
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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 |
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pubmed:status |
MEDLINE
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pubmed:month |
Oct
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pubmed:issn |
0022-3751
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
496 ( Pt 1)
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
255-64
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pubmed:dateRevised |
2010-8-25
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pubmed:meshHeading |
pubmed-meshheading:8910213-Animals,
pubmed-meshheading:8910213-Calcium,
pubmed-meshheading:8910213-Electrophysiology,
pubmed-meshheading:8910213-Exocytosis,
pubmed-meshheading:8910213-Guanosine 5'-O-(3-Thiotriphosphate),
pubmed-meshheading:8910213-Guanosine Diphosphate,
pubmed-meshheading:8910213-Guanosine Triphosphate,
pubmed-meshheading:8910213-Islets of Langerhans,
pubmed-meshheading:8910213-Kinetics,
pubmed-meshheading:8910213-Membrane Potentials,
pubmed-meshheading:8910213-Mice,
pubmed-meshheading:8910213-Patch-Clamp Techniques,
pubmed-meshheading:8910213-Thionucleotides
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pubmed:year |
1996
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pubmed:articleTitle |
Ca(2+)- and GTP-dependent exocytosis in mouse pancreatic beta-cells involves both common and distinct steps.
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pubmed:affiliation |
University Laboratory of Physiology, Oxford, UK.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
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