title: The glucose transporter-2 (GLUT2) is a low affinity dehydroascorbic acid transporter.
abstract: We studied the acquisition of dehydroascorbic acid by rat hepatocytes, H4IIE rat hepatoma cells and Xenopus laevis oocytes. Transport kinetics and competition and inhibition studies revealed that rat hepatocytes transport oxidized dehydroascorbic acid through a single functional component possessing the functional and kinetic properties expected for the glucose transporter GLUT2. On the other hand, rat hepatoma cells showed expression of at least two dehydroascorbic acid transporters with the expected functional and kinetic properties expected for GLUT1 and GLUT2. Expression studies of GLUT2 in X. laevis oocytes followed by transport kinetics and competition and inhibition studies revealed that GLUT2 is a low affinity dehydroascorbic transporter whose kinetic and functional properties match those observed for the endogenous GLUT2 transporter in rat hepatocytes and rat hepatoma cells. Therefore, GLUT2, a transporter known as a low affinity transporter of glucose and fructose and a high affinity transporter of glucosamine is also a low affinity dehydroascorbic acid transporter.
authors.affiliation: Departamento de Ciencias Básicas, Universidad Católica de la Santísima Concepción, Concepción, Chile.
authors.forename: Lorena
authors.initials: L
authors.lastname: Mardones
authors.forename: Valeska
authors.initials: V
authors.lastname: Ormazabal
authors.forename: Ximena
authors.initials: X
authors.lastname: Romo
authors.forename: Claudia
authors.initials: C
authors.lastname: Jaña
authors.forename: Pablo
authors.initials: P
authors.lastname: Binder
authors.forename: Eduardo
authors.initials: E
authors.lastname: Peña
authors.forename: Marilyn
authors.initials: M
authors.lastname: Vergara
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Zúñiga
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D003683:Dehydroascorbic Acid / Q000378:metabolism*; D051273:Glucose Transporter Type 2 / Q000235:genetics / Q000378:metabolism*; D022781:Hepatocytes / Q000378:metabolism*; D009865:Oocytes; D051381:Rats; D014982:Xenopus laevis
chemical_list: D051273:Glucose Transporter Type 2; C495683:Slc2a2 protein, rat; D003683:Dehydroascorbic Acid