The mechanism of uptake of ascorbic acid into osteoblasts and leukocytes.
Ascorbic acid is taken up into osteoblast cells by a saturable, stereospecific, Na(+)-dependent transporter, accumulating ascorbic acid to a level 100-fold that in the medium. The ascorbic acid uptake rate correlated with intracellular hydroxyproline synthesis. A second, distinct mechanism has also been described for accumulation of ascorbic acid into neutrophils and myeloid leukemia cells. This appears to be Na(+)-independent and relies on the glucose transporter GLUT1 to ferry dehydroascorbic acid (DHA) into cells and then to trap it as ascorbic acid to a high concentration.
Wolf
G
G
Department of Nutritional Sciences, University of California at Berkeley 94720-3104, USA.
D000818:Animals; D001205:Ascorbic Acid / Q000493:pharmacokinetics*; D002478:Cells, Cultured; D051272:Glucose Transporter Type 1; D006909:Hydroxyproline / Q000096:biosynthesis / Q000502:physiology; D007962:Leukocytes / Q000378:metabolism*; D051379:Mice; D009004:Monosaccharide Transport Proteins / Q000502:physiology; D010006:Osteoblasts / Q000378:metabolism*
D051272:Glucose Transporter Type 1; D009004:Monosaccharide Transport Proteins; C495678:Slc2a1 protein, mouse; D001205:Ascorbic Acid; D006909:Hydroxyproline