STUDIES ON LIPID-PEROXIDATION AND PROTEIN OXIDATION IN THE AGING BRAIN

Lipid peroxidation (LP) and protein oxidation (PO) were investigated i n hippocampus and frontal cortex homogenates from young (5 months), ma ture (13 months) and old (24 months) Wistar rats and young (5 months) and old (24 months) Brown Norway rats. LP and PO were determined in ba sal conditions and after incubation without iron (spontaneous conditio n) or with iron (stimulated condition). LP was measured as HPLC-assaye d malondialdehyde (MDA) and PO as protein carbonyl (GO) content. Brain homogenates formed considerable amounts of MDA and CO spontaneously a nd, to an even greater extent, in the presence of Fe2+. Old rats showe d greater iron-stimulated LP in the cortex than young rats, but the di fference was not significant. Basal (but not spontaneous or stimulated ) PO was significantly increased (19%) in the hippocampus of old compa red to young rats. This study does not confirm the age-related increas e in LP reported in the literature and only partially confirms the fin dings concerning PO.