Lefebvre V, Buc-Calderon P
Departement des Sciences Pharmaceutiques, Universite Catholique de Louvain, Bruxelles, Belgium.
Isolated hepatocytes incubated under hypoxic conditions were more sensitive
to H2O2-mediated injury as compared to cells kept under aerobic conditions,
but only for the highest H2O2 concentration tested (8 mM). At lower concentrations
(2 and 4 mM) cells were still able to detoxify H2O2 even under hypoxic
conditions. Reoxygenation of hypoxic hepatocytes did not result in a cytolytic
effect, whereas reoxygenation in the presence of H2O2 resulted in an enhanced
cytotoxicity. The duration of previous hypoxia (before H2O2 addition) did
not affect the lytic effect induced by H2O2. Enzymatic activities of both
catalase and glutathione peroxidase were unchanged over 2 h of incubation
under hypoxic conditions. Preincubation of hepatocytes in the presence
of Desferal (5 mM) resulted in the abolition of H2O2-mediated lytic effects.
A role for free iron, released from intracellular stores and acting on
H2O2 to yield reactive oxygen species is discussed.
PMID: 7820879, UI: 95120843