External hydrogen peroxide is not indispensable for experimental induction of lipid peroxidation via Fenton reaction in porcine ovary homogenates.

OBJECTIVE: Substrates of Fenton reaction (Fe(2+)+H(2)O(2)-->Fe(3+)+*OH+OH-) may be used to experimentally induce oxidative damage to macromolecules. The study aimed at evaluating effects of Fe(2+) and/or H(2)O(2) on lipid peroxidation in porcine ovary homogenates.
MATERIALS AND METHODS: Ovary homogenates were incubated in the presence of either H2O2 (100, 50, 25, 10, 5.0, 2.5, 1.0, 0.5, 0.25, 0.01, 0.001 mM) or FeSO(4) (Fe2+) (300, 150, 75, 30, 15, 7.5, 3.0, 1.5, 0.75 microM), or of those two factors used together: Fe(2+) (30 microM) plus H(2)O(2) (concentrations as above), or H(2)O(2) (0.5 mM) plus Fe(2+) (concentrations as above). The concentration of malondialdehyde+4-hydroxyalkenals constituted the lipid peroxidation index.
RESULTS: H(2)O(2) alone did not affect lipid peroxidation in porcine ovary homogenates at all, whereas Fe(2+) (300, 150, 75, 30, and 15 microM) alone increased lipid peroxidation in a concentration dependent manner. When Fe(2+) and H(2)O(2) were applied together, lipid peroxidation increased significantly without any concentration related effect of H(2)O(2), but with a clear concentration dependent effect of Fe(2+); the damaging effect of Fe(2+), used together with H(2)O(2), was the same as the one, obtained after Fe(2+) was applied alone.
CONCLUSIONS: In conclusion, external H(2)O(2) is not indispensable for experimental induction of lipid peroxidation by Fenton reaction in porcine ovary homogenates.