4-Hydroxynonenal content lower in brains of 25 month old transgenic mice carrying the human CuZn superoxide dismutase gene than in brains of their non-transgenic littermates.

Basic peroxidation in brains of normal 2 month old mice was compared to that in brains of 25 month old mice by measurement of 4-hydroxy-2-nonenal and protein carbonyl contents. No significant age-related differences in 4-hydroxy-2-nonenal were observed, showing that lipid peroxidation is not a determining factor in cerebral aging. However, protein carbonyls increased with age in brains, indicating accumulation of age-related cell constituent damage.

Is malonaldehyde a valuable indicator of lipid peroxidation?

Malonaldehyde (MDA), a decomposition product of lipid hydroperoxides which is used as an indicator of oxidative damage to cells and tissues, reacts, in vitro, with hydrogen peroxide to form undetermined degradation products. Since human polymorphonuclear leukocytes (PMNs) release reactive oxygen species including hydrogen peroxide when stimulated with phorbol myristate acetate (PMA), we incubated specific amounts of MDA with resting PMNs and PMA-stimulated PMNs. The amount of MDA recovered after 30 min incubation with stimulated cells, as determined by MDA-thiobarbituric acid assay, was 25% lower than that recovered with resting cells.