Characterization of glucose transport by bovine retinal capillary pericytes in culture.
The transport of D-glucose and its non-metabolizable analog, 3-o-methyl-D-glucose (3-o-MG), by cultured bovine retinal capillary pericytes was characterized. A preference for D-glucose over L-glucose uptake by pericytes indicated a stereospecific process. The 3-o-MG transport appeared to follow complex kinetics. At low substrate concentrations, 3-o-MG transport had an apparent Km of 1.53 mM and a Vmax of 0.50 nmol (microgram DNA)-1 min-1 at 37 degrees C. A reduced extracellular sodium concentration, energy poisons, and exogenous insulin did not significantly influence 3-o-MG uptake. Inhibition of the uptake or efflux of 3-o-MG by cytochalasin B or phloretin, respectively, and the demonstration of a 'counter transport' phenomenon showed that 3-o-MG transport by retinal capillary pericytes in culture was a carrier-mediated process.
D019325:3-O-Methylglucose; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002196:Capillaries; D002417:Cattle; D002478:Cells, Cultured; D003571:Cytochalasin B / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology; D007700:Kinetics; D008757:Methylglucosides / Q000378:metabolism; D010693:Phloretin / Q000494:pharmacology; D012171:Retinal Vessels / Q000378:metabolism*; D013237:Stereoisomerism
D007328:Insulin; D008757:Methylglucosides; D019325:3-O-Methylglucose; D003571:Cytochalasin B; D005947:Glucose; D010693:Phloretin