title: The labile iron pool of hepatocytes in chronic and acute iron overload and chelator-induced iron deprivation.
abstract: BACKGROUND
  The cytosolic labile iron pool (LIP) is a transitory, catalytically active compartment that has been implicated in cell iron homeostasis and in metal-induced cytotoxicity.
  
  
  OBJECTIVE
  We attempted to define LIP levels in living hepatocytes derived from chronic overloaded rats and from normal hepatocytes either acutely loaded with iron or depleted by chelation.
  
  
  METHODS
  LIP levels were measured in living rat hepatocytes derived from normal and iron-fed rats.
  
  
  RESULTS
  Steady-state LIP levels in untreated hepatocytes ( approximately 0.2 microM) were raised by 1.8-fold following iron loading and were reduced by 0.66-fold by short-term chelation treatment. Changes in LIP were accompanied by the corresponding changes in iron-responsive protein (IRP) activity and ferritin levels, that, in rat hepatocytes isolated from chronically loaded animals, raised by approximately 19-fold.
  
  
  CONCLUSIONS
  Whereas ferritin levels provide an index of long-term or cumulative iron loading, LIP measurements provide an "instantaneous" parameter of iron availability within hepatocytes. The latter was associated with the cell chelatable pool in cells derived from normal and iron-loaded animals, both of which showed similar accessibility to iron chelators.
authors.affiliation: Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91120, Israel. gzanninelli@hotmail.com
authors.forename: Giuliana
authors.initials: G
authors.lastname: Zanninelli
authors.forename: Olivier
authors.initials: O
authors.lastname: Loréal
authors.forename: Pierre
authors.initials: P
authors.lastname: Brissot
authors.forename: Abraham M
authors.initials: AM
authors.lastname: Konijn
authors.forename: Itzchak N
authors.initials: IN
authors.lastname: Slotki
authors.forename: Robert C
authors.initials: RC
authors.lastname: Hider
authors.forename: Z
authors.initials: Z
authors.lastname: Ioav Cabantchik
mesh_terms: D000208:Acute Disease; D000818:Animals; D002908:Chronic Disease; D003600:Cytosol / Q000378:metabolism; D005293:Ferritins / Q000378:metabolism; D005452:Fluoresceins; D005453:Fluorescence; D022781:Hepatocytes / Q000378:metabolism*; D007501:Iron / Q000493:pharmacokinetics*; D007502:Iron Chelating Agents / Q000494:pharmacology; D000090463:Iron Deficiencies; D019190:Iron Overload / Q000378:metabolism*; D008099:Liver / Q000166:cytology / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D005452:Fluoresceins; D007502:Iron Chelating Agents; D005293:Ferritins; D007501:Iron; C007740:fluorexon