title: Ascorbate is regenerated by HL-60 cells through the transplasmalemma redox system.
abstract: Ascorbate was maintained in the media during a long-term culture by HL-60 cells. The chemical oxidation of ascorbate was reversed in vitro by living HL-60 cells and was related to the amount of cells added. The increase of NADH concentration by lactate addition to cells was accompanied by an increase of both ascorbate regeneration and ferricyanide reduction. Further, plasma membrane enriched fractions from HL-60 cells revealed enhancement of both ascorbate regeneration and ferricyanide reduction in the presence of NADH when previously treated with detergent. The blockage of cell surface carbohydrates by wheat germ agglutinin (WGA) and Concanavalina ensiformis (Con A) lectins significantly inhibited the regeneration of ascorbate caused by the cells. These results support the idea that ascorbate is externally regenerated by the NADH-ascorbate free radical reductase as a part of the transplasma membrane redox system.
authors.affiliation: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Córdoba, Spain.
authors.forename: F J
authors.initials: FJ
authors.lastname: Alcain
authors.forename: M I
authors.initials: MI
authors.lastname: Buron
authors.forename: J M
authors.initials: JM
authors.lastname: Villalba
authors.forename: P
authors.initials: P
authors.lastname: Navas
mesh_terms: D001205:Ascorbic Acid / Q000378:metabolism* / Q000494:pharmacology; D002452:Cell Count; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D003208:Concanavalin A / Q000494:pharmacology; D003683:Dehydroascorbic Acid / Q000378:metabolism; D005292:Ferricyanides / Q000378:metabolism; D005609:Free Radicals; D006801:Humans; D007700:Kinetics; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D009243:NAD / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D014909:Wheat Germ Agglutinins / Q000494:pharmacology
chemical_list: D005292:Ferricyanides; D005609:Free Radicals; D007773:Lactates; D014909:Wheat Germ Agglutinins; D009243:NAD; D003208:Concanavalin A; C007931:hexacyanoferrate III; D019344:Lactic Acid; D009247:NADH, NADPH Oxidoreductases; C023927:monodehydroascorbate reductase (NADH); D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid