Oxidative stress and lipid peroxidation may contribute to the pathology of
neurodegenerative disorders such as
Alzheimer's disease (AD) and
cerebral ischemia.
4-Hydroxynonenal (4-HNE) is a toxic by-product of lipid peroxidation, and immunoreactivity to 4-HNE has been used to examine lipid peroxidation in the pathogenesis of AD and
ischemia. This study sought to determine 1) if there are cellular alterations in 4-HNE immunoreactivity in the human hippocampus after global
ischemia, and 2) whether possession of an
apolipoprotein E (
APOE) epsilon4 allele influenced the extent of 4-HNE immunoreactivity. 4-HNE immunoreactivity was assessed semi-quantitatively in the temporal lobe of a group of controls (n = 44) and in a group of patients who had an episode of global
ischemia as a result of a cardiorespiratory arrest and subsequently died (n = 56, survival ranged from 1hr to 42 days). There was minimal cellular 4-HNE immunoreactivity in the control group. However, compared to controls, 4-HNE immunoreactivity was significantly increased in neurons (p < 0.0002) and glia (p < 0.0001) in the hippocampal formation after global
ischemia. Possession of an
APOE epsilon4 allele did not influence the extent of neuronal or glial 4-HNE immunostaining in the control or global
ischemia group. There was a significant negative correlation between the extent of neuronal 4-HNE immunoreactivity with survival period after global
ischemia (r2 = 0.0801; p < 0.036) and a significant positive correlation between the extent of glial 4-HNE immunoreactivity and survival after global
ischemia (r2 = 0.2958; p < 0.0001). The data indicate a marked increase in neuronal and glial 4-HNE. This substantiates a role for lipid peroxidation in the pathogenesis of
cerebral ischemia. There was no indication that
APOE genotype influenced the extent of 4-HNE immunoreactivity.