title: Cytoprotection and iron mobilization in rat hepatocyte cultures by a new synthetic dihydroxamate chelator.
abstract: The cytoprotection and iron mobilization effect of a new dihydroxamate chelator 1,1 bis [(11-N-hydroxy)-2,5,11-triaza-1,6,10-trioxo dodecanyl] ethane or KD was studied in primary rat hepatocyte cultures exposed to iron-citrate. Lactate dehydrogenase (LDH) release and malondialdehyde (MDA) production were measured as indexes of cytotoxicity. Cell viability was evaluated using the [3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyl tetrazolium bromide] (MTT) reduction test. To demonstrate that this chelator was able to decrease iron uptake or increase iron release from the hepatocytes, labelled cells were obtained by maintaining the cultures in the presence of 0.02 microM 55Fe-citrate. The efficacy of KD was compared to desferrioxamine B (DFO) at stoechiometry concentrations. After 24 h of exposure to 50 microM of iron-citrate, a significant release of LDH and MDA was observed. Cell viability was also significantly decreased. When 100 microM of KD were added at the same time as iron, LDH and MDA release was decreased and cell viability was improved. In the presence of the same chelator concentration, a net decrease of iron uptake by the cells was observed as attested by the low intracellular 55Fe level. Moreover, in the 55Fe loaded hepatocytes, the chelator increased the iron extracellular level indicating its iron release effect from the cells. In all tested experimental conditions, the efficacy of 100 microM of the dihydroxamate chelator KD was close to that of 50 microM of the trihydroxamate chelator DFO. In conclusion, KD is effective at a level comparable to DFO in protecting rat hepatocytes against the toxic effect of iron-citrate by decreasing the uptake of the metal and increasing its release from the cells. This synthetic compound appears to have some potential therapeutical interest and the results obtained encourage the synthesis of new hydroxamate ligands.
authors.affiliation: INSERM U522, Régulations des Equilibres Fonctionnels du Foie Normal et Pathologique, Hôpital de Pontchaillou, Rennes, France.
authors.forename: N
authors.initials: N
authors.lastname: Rakba
authors.forename: M K
authors.initials: MK
authors.lastname: Nguyen-Van-Duong
authors.forename: L
authors.initials: L
authors.lastname: Nicolas
authors.forename: V
authors.initials: V
authors.lastname: Guillot
authors.forename: I
authors.initials: I
authors.lastname: Morel
authors.forename: N
authors.initials: N
authors.lastname: Pasdeloup
authors.forename: P
authors.initials: P
authors.lastname: Brissot
authors.forename: G
authors.initials: G
authors.lastname: Lescoat
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D004396:Coloring Agents; D006877:Hydroxamic Acids / Q000494:pharmacology*; D007501:Iron / Q000378:metabolism*; D007502:Iron Chelating Agents / Q000378:metabolism*; D007504:Iron Radioisotopes; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: C402105:1,1-bis-((11-N-hydroxy)-2,5,11-triaza-1,6,10-trioxo dodecanyl)ethane; D004396:Coloring Agents; D006877:Hydroxamic Acids; D007502:Iron Chelating Agents; D007504:Iron Radioisotopes; D013778:Tetrazolium Salts; D013844:Thiazoles; D007501:Iron; D007770:L-Lactate Dehydrogenase; C022616:thiazolyl blue