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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6 Pt 1
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pubmed:dateCreated |
1992-7-29
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pubmed:abstractText |
To investigate the role of D-myo-inositol 1,3,4,5-tetrakisphosphate [Ins(1,3,4,5)P4] in the regulation of Ca2+ influx, we injected inositol phosphates into Xenopus oocytes and measured Ca(2+)-gated Cl- current to assay intracellular free Ca2+ concentration ([Ca2+]i). To assess Ca2+ influx, we removed extracellular Ca2+ or added the inorganic Ca2+ channel blocker Mn2+ to the extracellular bath and measured the resulting change in Cl- current. Ins(1,3,4,5)P4 did not cause Ca2+ influx when injected alone or when preceded by an injection of Ca2+. In contrast, Ins(1,3,4,5)P4 stimulated Ca2+ influx when injected after the poorly metabolized inositol trisphosphate (InsP3) analogues D-myo-inositol 1,4,5-trisphosphorothioate [Ins(1,4,5)P3S3] or D-myo-inositol 2,4,5-trisphosphate [Ins(2,4,5)P3]. These results indicate that Ins(1,3,4,5)P4 is not sufficient to stimulate Ca2+ influx but acts in synergy with InsP3s to cause Ca2+ influx. We also studied the effect of Ca2+ influx on the immediate metabolism of D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] in single oocytes. Ca2+ influx shunted the metabolism of Ins(1,4,5)P3 toward the formation of Ins(1,3,4,5)P4 and away from D-myo-inositol 1,4-bisphosphate [Ins(1,4)P2]. These results suggest that there is a positive feedback regulatory mechanism in which Ca2+ influx stimulates Ins(1,3,4,5)P4 production and Ins(1,3,4,5)P4 stimulates further Ca2+ influx.
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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/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Chloride Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Inositol 1,4,5-Trisphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Inositol Phosphates,
http://linkedlifedata.com/resource/pubmed/chemical/Ion Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Manganese,
http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/inositol-1,3,4,5-tetrakisphosphate
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pubmed:status |
MEDLINE
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pubmed:month |
Jun
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pubmed:issn |
0002-9513
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
262
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
C1456-63
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:1377444-Animals,
pubmed-meshheading:1377444-Biological Transport,
pubmed-meshheading:1377444-Calcium,
pubmed-meshheading:1377444-Chloride Channels,
pubmed-meshheading:1377444-Chromatography, High Pressure Liquid,
pubmed-meshheading:1377444-Drug Synergism,
pubmed-meshheading:1377444-Female,
pubmed-meshheading:1377444-Inositol 1,4,5-Trisphosphate,
pubmed-meshheading:1377444-Inositol Phosphates,
pubmed-meshheading:1377444-Ion Channels,
pubmed-meshheading:1377444-Kinetics,
pubmed-meshheading:1377444-Manganese,
pubmed-meshheading:1377444-Membrane Proteins,
pubmed-meshheading:1377444-Oocytes,
pubmed-meshheading:1377444-Time Factors,
pubmed-meshheading:1377444-Xenopus laevis
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pubmed:year |
1992
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pubmed:articleTitle |
InsP3 and Ins(1,3,4,5)P4 act in synergy to stimulate influx of extracellular Ca2+ in Xenopus oocytes.
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pubmed:affiliation |
Howard Hughes Medical Institute, Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
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