title: Menadione metabolism to thiodione in hepatoblastoma by scanning electrochemical microscopy.
abstract: The cytotoxicity of menadione on hepatocytes was studied by using the substrate generation/tip collection mode of scanning electrochemical microscopy by exposing the cells to menadione and detecting the menadione-S-glutathione conjugate (thiodione) that is formed during the cellular detoxication process and is exported from the cell by an ATP-dependent pump. This efflux was electrochemically detected and allowed scanning electrochemical microscopy monitoring and imaging of single cells and groups of highly confluent live cells. Based on a constant flux model, approximately 6 x 10(6) molecules of thiodione per cell per second are exported from monolayer cultures of Hep G2 cells.
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas, 1 University Station, A5300, Austin, TX 78712, USA.
authors.forename: Janine
authors.initials: J
authors.lastname: Mauzeroll
authors.forename: Allen J
authors.initials: AJ
authors.lastname: Bard
authors.forename: Omeed
authors.initials: O
authors.lastname: Owhadian
authors.forename: Terrence J
authors.initials: TJ
authors.lastname: Monks
mesh_terms: D045744:Cell Line, Tumor; D004563:Electrochemistry; D005978:Glutathione / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism*; D018197:Hepatoblastoma / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008658:Inactivation, Metabolic; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008853:Microscopy / Q000379:methods*; D015394:Molecular Structure; D013997:Time Factors; D024483:Vitamin K 3 / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity
chemical_list: C495859:menadione-S-glutathione conjugate; D024483:Vitamin K 3; D005978:Glutathione