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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1990-8-17
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pubmed:abstractText |
Inositol uptake was studied in the rat CNS neuroblastoma B50 cell line. Eadie-Hofstee analysis of the uptake pattern reveals two defined modes of inositol entry into the cell. The high-affinity uptake component requires the presence of extracellular sodium and is inhibited by phloridzin. Analysis of the uptake velocities of the high-affinity uptake component provided the following apparent kinetic parameters: Km = 13.7 microM and Vmax = 14.7 pmol/mg of protein/min (without correcting for residual diffusion) and Km = 12.9 microM and Vmax = 12.3 pmol/mg of protein/min (with correction). At physiological concentrations, the high-affinity transport process contributes approximately 70% to total uptake; the remainder is due to a low-affinity diffusion-like process. Uptake inhibition studies reveal that the uptake process is sensitive to ouabain, amiloride, and dichlorobenzamil inhibition but relatively insensitive to cytochalasin B or phloretin. When neuroblastoma B50 cells are induced to differentiate morphologically with high extracellular calcium or with dibutyryl cyclic AMP, a significant decrease in inositol uptake is observed. The dibutyryl cyclic AMP-mediated inhibition of uptake affects only the high-affinity uptake component and is noncompetitive in nature. The high extracellular calcium-mediated inhibition is less specific; it involves "disappearance" of the high-affinity process, some inhibition of the low-affinity process, and an increase of inositol efflux. The significance of these observations is discussed in the context of neuroblastoma B50 cell differentiation.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/3',4'-dichlorobenzamil,
http://linkedlifedata.com/resource/pubmed/chemical/Amiloride,
http://linkedlifedata.com/resource/pubmed/chemical/Bucladesine,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Cytochalasin B,
http://linkedlifedata.com/resource/pubmed/chemical/Inositol,
http://linkedlifedata.com/resource/pubmed/chemical/Ouabain,
http://linkedlifedata.com/resource/pubmed/chemical/Phloretin,
http://linkedlifedata.com/resource/pubmed/chemical/Phlorhizin,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium
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pubmed:status |
MEDLINE
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pubmed:month |
Aug
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pubmed:issn |
0022-3042
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
55
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
641-50
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2164574-Amiloride,
pubmed-meshheading:2164574-Animals,
pubmed-meshheading:2164574-Biological Transport,
pubmed-meshheading:2164574-Bucladesine,
pubmed-meshheading:2164574-Calcium,
pubmed-meshheading:2164574-Cell Differentiation,
pubmed-meshheading:2164574-Cytochalasin B,
pubmed-meshheading:2164574-Inositol,
pubmed-meshheading:2164574-Kinetics,
pubmed-meshheading:2164574-Neuroblastoma,
pubmed-meshheading:2164574-Ouabain,
pubmed-meshheading:2164574-Phloretin,
pubmed-meshheading:2164574-Phlorhizin,
pubmed-meshheading:2164574-Rats,
pubmed-meshheading:2164574-Sodium,
pubmed-meshheading:2164574-Tumor Cells, Cultured
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pubmed:year |
1990
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pubmed:articleTitle |
Inositol metabolism during neuroblastoma B50 cell differentiation: effects of differentiating agents on inositol uptake.
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pubmed:affiliation |
Department of Biological Sciences, Rutgers University, Newark, NJ 07102.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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