title: Liver preconditioning induced by iron in a rat model of ischemia/reperfusion.
abstract: OBJECTIVE
  Liver preconditioning against ischemia-reperfusion (IR) injury is a major area of experimental research, in which regulation of gene expression with cytoprotective responses due to transient oxidative stress development has been reported. Considering that significant cytoprotection occurs after exposure to low levels of iron (Fe), we tested the hypothesis that sub-chronic administration of Fe to rats underlying transient oxidative stress preconditions the liver against IR injury.
  
  
  METHODS
  Animals received six doses (50 mg Fe-dextran/kg ip) every second day during 10 days, before partial IR (vascular clamping) or sham laparotomy (control). Transient oxidative stress was defined by liver glutathione and protein carbonyl contents (24, 48, and 72 h after Fe treatment). Plasma and liver Fe status and ferritin content (western blot) were assessed in animals not subjected to IR. Liver injury and inflammatory response were evaluated by serum transaminases, liver morphology and serum TNF-α. Fe preconditioning against IR injury was correlated with liver glutathione content and the redox-sensitive NF-κB signaling pathway (EMSA) and western blot analysis of haptoglobin.
  
  
  RESULTS
  Significant hepatoprotection against IR injury, underlying transient oxidative stress and enhancement in the total and labile Fe pools, was achieved by Fe administration. Abrogation of IR injury is related to reduced TNF-α response (91%), abolishment of the IR-induced liver glutathione depletion and recovery of the NF-κB signaling pathway (75%), lost during IR.
  
  
  CONCLUSIONS
  Sub-chronic Fe administration protects the liver against IR injury through antioxidant and anti-inflammatory responses, with recovery of NF-κB activation and related acute-phase response signaling.
authors.affiliation: Physical Chemistry-PRALIB, School of Pharmacy and Biochemistry, University of Buenos Aires-CONICET, Buenos Aires, Argentina.
authors.forename: Mónica
authors.initials: M
authors.lastname: Galleano
authors.forename: Gladys
authors.initials: G
authors.lastname: Tapia
authors.forename: Susana
authors.initials: S
authors.lastname: Puntarulo
authors.forename: Patricia
authors.initials: P
authors.lastname: Varela
authors.forename: Luis A
authors.initials: LA
authors.lastname: Videla
authors.forename: Virginia
authors.initials: V
authors.lastname: Fernández
mesh_terms: D000210:Acute-Phase Reaction / Q000378:metabolism; D000818:Animals; D004195:Disease Models, Animal; D005978:Glutathione / Q000172:deficiency / Q000378:metabolism; D007501:Iron / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D019194:Ischemic Preconditioning / Q000379:methods*; D008099:Liver / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology; D008297:Male; D016328:NF-kappa B / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000517:prevention & control*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D007501:Iron; D005978:Glutathione