Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
10
|
pubmed:dateCreated |
1990-11-21
|
pubmed:abstractText |
Measurements of initial glucose entry rate and intracellular glucose concentration in cultured cells are difficult because of rapid transport relative to intracellular volume and a substantial extracellular space from which glucose cannot be completely removed by quick exchanges of medium. In 3T3-L1 cells, we obtained good estimates of initial entry of [14C]methylglucose and D-[14C]glucose with 1) L-[3H]glucose as an extracellular marker together with the [14C]glucose or [14C]methylglucose in the substrate mixture, 2) sampling times as short as 2 s, 3) ice-cold phloretin-containing medium to stop uptake and rinse away the extracellular label, and 4) nonlinear regression of time courses. Methylglucose equilibrated in two phases--the first with a half-time of 1.7 s and the second with a half-time of 23 s; it eventually equilibrated in an intracellular space of 8 microliters/mg protein. Entry of glucose remained almost linear for 10 s, making its transport kinetics easier to study (Km = 5.7 mM, Vmax = 590 nmol.s-1.ml-1 cell water). Steady-state intracellular glucose concentration was 75-90% of extracellular glucose concentration. Cells grown in a high-glucose medium (24 mM) exhibited a 67% reduction of glucose-transport activity and a 50% reduction of steady-state ratio of intracellular glucose to extracellular glucose.
|
pubmed:grant | |
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
AIM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
|
pubmed:month |
Oct
|
pubmed:issn |
0012-1797
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
39
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
1228-34
|
pubmed:dateRevised |
2007-11-14
|
pubmed:meshHeading |
pubmed-meshheading:2210075-Animals,
pubmed-meshheading:2210075-Biological Transport, Active,
pubmed-meshheading:2210075-Carbon Radioisotopes,
pubmed-meshheading:2210075-Cell Line,
pubmed-meshheading:2210075-Fibroblasts,
pubmed-meshheading:2210075-Glucose,
pubmed-meshheading:2210075-Kinetics,
pubmed-meshheading:2210075-Methylglucosides,
pubmed-meshheading:2210075-Mice,
pubmed-meshheading:2210075-Radioisotope Dilution Technique,
pubmed-meshheading:2210075-Tritium
|
pubmed:year |
1990
|
pubmed:articleTitle |
Evidence that downregulation of hexose transport limits intracellular glucose in 3T3-L1 fibroblasts.
|
pubmed:affiliation |
Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
|
pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|