title: The decrease of cytochrome c oxidase activity by 15-deoxyspergualin results in enhancement of XTT reduction in cultured cells.
abstract: Exposure to immunosuppressant, 15-deoxyspergualin (DSG) induced enhanced formazan producing activity from XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carb oxanilide, sodium salt) in cultured cells, but not from MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). Formazan generation from XTT is known to be stimulated by cytochrome c oxidase (COX) inhibitors such as KCN and NaN3, whereas MTT reduction is not affected by them. So, the effect of DSG on COX was examined. DSG did not directly inhibit the enzyme, but the cellular enzyme activity was decreased by exposure to DSG. It was thought that stimulation of XTT reduction by DSG resulted from the decrease of cellular cytochrome c oxidase activity.
authors.affiliation: Institute of Microbial Chemistry, Tokyo, Japan.
authors.forename: C
authors.initials: C
authors.lastname: Nosaka
authors.forename: S
authors.initials: S
authors.lastname: Kunimoto
authors.forename: T
authors.initials: T
authors.lastname: Takeuchi
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003576:Electron Transport Complex IV / Q000187:drug effects* / Q000378:metabolism; D006146:Guanidines / Q000494:pharmacology*; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D010084:Oxidation-Reduction; D013778:Tetrazolium Salts / Q000378:metabolism*
chemical_list: D006146:Guanidines; D007166:Immunosuppressive Agents; D013778:Tetrazolium Salts; C059087:2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino)carbonyl)-2H-tetrazolium hydroxide; D003576:Electron Transport Complex IV; C037258:gusperimus