Evidence of sodium-dependent glucose transport in human erythroleukemia cells.
Sodium-dependent transport of D-glucose has been reported only in epithelial cells of small intestine and kidney, and well-differentiated tumors thereof. We observed a two-fold decrease (p < 0.05) in the intracellular distribution volume (Vic, defined as steady-state intracellular uptake divided by extracellular concentration) of the non-metabolized D-glucose analog 3-O-methylglucose (3-O-MG) when logarithmically growing K562 cells (an anaplastic human erythroleukemia) were incubated 3 h in choline-substituted, phosphate buffered saline (PBS) rather than Na+ PBS, each containing a glucose concentration ([Glu]) of 5.6 mM. Electromechanically measured cellular volume Vc differed < 10% between the different media. In Na+ PBS, Vic (3-O-MG) was approximately twice Vc and declined progressively when [Glu] was reduced to 2.8 and 0.1 mM. We conclude that, in a balanced salt medium containing glucose as the only energy source, K562 cells express a concentrative mechanism having characteristics consistent with Na(+)-dependent transport of glucose.
Bading
J R
JR
Department of Radiology, University of Southern California, Los Angeles 90033, USA.
Mircheff
A K
AK
Kan-Mitchell
J
J
D019325:3-O-Methylglucose; D001692:Biological Transport; D048429:Cell Size; D005947:Glucose / Q000378:metabolism*; D006019:Glycolysis; D006801:Humans; D004915:Leukemia, Erythroblastic, Acute / Q000378:metabolism / Q000473:pathology; D008757:Methylglucosides / Q000378:metabolism; D010085:Oxidative Phosphorylation; D012964:Sodium / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D008757:Methylglucosides; D019325:3-O-Methylglucose; D012964:Sodium; D005947:Glucose