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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
27
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pubmed:dateCreated |
1988-10-19
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pubmed:abstractText |
The cytoplasmic calcium concentration (Ca2+i) was measured in suspensions of fura-2 loaded mouse pancreatic beta-cells by continuously recording the 340/380 nm fluorescence excitation ratio. When the glucose concentration was raised from 3 to 20 mM, there was an initial lowering of Ca2+i followed by a sustained increase. Whereas the reduction in Ca2+i was related to the extracellular glucose concentration in a hyperbolic manner, the increasing component exhibited a sigmoidal dose-response relationship. Both effects became maximal at 15-20 mM of the sugar. Qualitatively similar bimodal Ca2+i responses were obtained with 30 mM mannose, 2 mM alpha-ketoisocaproic acid, 10 mM leucine, and 10 mM metabolism-stimulating leucine analogue beta-2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid. Fructose (30 mM) had virtually no effect on Ca2+i in the presence of extracellular Ca2+, and 10 mM arginine induced only a rise. The results indicate that nutrient secretagogues stimulate both the entry of Ca2+ into the beta-cells and its elimination from the cytoplasm by processes like organelle sequestration and outward transport. Consequently, the Ca2+i level determining insulin secretion results from the balance between two opposing actions.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/2-aminobicyclo(2,2,1)heptane-2-carbo...,
http://linkedlifedata.com/resource/pubmed/chemical/Amino Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Amino Acids, Cyclic,
http://linkedlifedata.com/resource/pubmed/chemical/Arginine,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Glucose,
http://linkedlifedata.com/resource/pubmed/chemical/Glutamine,
http://linkedlifedata.com/resource/pubmed/chemical/Insulin,
http://linkedlifedata.com/resource/pubmed/chemical/Keto Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Leucine,
http://linkedlifedata.com/resource/pubmed/chemical/alpha-ketoisocaproic acid
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pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
25
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pubmed:volume |
263
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
13750-4
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pubmed:dateRevised |
2011-11-17
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pubmed:meshHeading |
pubmed-meshheading:3047130-Amino Acids,
pubmed-meshheading:3047130-Amino Acids, Cyclic,
pubmed-meshheading:3047130-Animals,
pubmed-meshheading:3047130-Arginine,
pubmed-meshheading:3047130-Calcium,
pubmed-meshheading:3047130-Cytoplasm,
pubmed-meshheading:3047130-Dose-Response Relationship, Drug,
pubmed-meshheading:3047130-Glucose,
pubmed-meshheading:3047130-Glutamine,
pubmed-meshheading:3047130-Insulin,
pubmed-meshheading:3047130-Islets of Langerhans,
pubmed-meshheading:3047130-Keto Acids,
pubmed-meshheading:3047130-Leucine,
pubmed-meshheading:3047130-Mice,
pubmed-meshheading:3047130-Mice, Obese,
pubmed-meshheading:3047130-Obesity
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pubmed:year |
1988
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pubmed:articleTitle |
Nutrient secretagogues induce bimodal early changes in cytoplasmic calcium of insulin-releasing ob/ob mouse beta-cells.
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pubmed:affiliation |
Department of Medical Cell Biology, Uppsala University, Sweden.
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pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't
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