2-Deoxyglucose transport by intestinal epithelial cells isolated from the chick.
Characteristics of 2-deoxyglucose uptake (2DG) by intestinal epithelial cells isolated from chickens were evaluated as a means of discriminating between the concentrative transport system for monosaccharides, associated with the mucosal brush border, and other possible routes of monosaccharide entry. 2DG was chosen as it is not a substrate for the mucosal transport system. The deoxysugar enters via a saturable pathway which is not Na+-dependent, is not inhibited by K+, does not accumulate solute against a concentration gradient; exhibits a high sensitivity to inhibition by phloretin; is relatively insensitive to phlorizin inhibition; and has low affinity [but high capacity relative to Na+-dependent mucosal transport of 3-O-methylglucose (3-OMG) and other monosaccharides]. These characteristics confirm those established in an earlier report for Na+-independent uptake of 3-OMG. Complications encountered in the use of 2DG as a test sugar include significant rates of metabolic conversion to an anionic form which presumably is a phosphorylated species. Methods for distinguishing between transport and subsequent metabolism are described. Inhibition of 2DG entry by several other sugars is described and inhibitory constants (K's) given for each.
D000818:Animals; D001667:Binding, Competitive; D001693:Biological Transport, Active; D002645:Chickens; D003837:Deoxy Sugars / Q000378:metabolism*; D003847:Deoxyglucose / Q000378:metabolism*; D004140:Dinitrophenols / Q000494:pharmacology; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism*; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008353:Mannitol / Q000494:pharmacology; D009005:Monosaccharides / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D010693:Phloretin / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology
D003837:Deoxy Sugars; D004140:Dinitrophenols; D009005:Monosaccharides; D008353:Mannitol; D010042:Ouabain; D003847:Deoxyglucose; D012964:Sodium; D011188:Potassium; D010693:Phloretin