REGIONAL MEMBRANE PHOSPHOLIPID ALTERATIONS IN ALZHEIMERS-DISEASE

Regional levels of membrane phospholipids [phosphatidylethanolamine (P E), phosphatidylinositol (PI), phosphatidylcholine (PC)] were measured in the brain of Alzheimer's disease (AD) and control subjects. The le vels of PE-derived and PI-derived total fatty acids were significantly decreased in the hippocampus of AD subjects. Here significant decreas es were found in PE-derived stearic, oleic and arachidonic and docosah exaenoic acids, and in PI-derived oleic and arachidonic acids. In the inferior parietal lobule of AD subjects, significant decreases were fo und only in PE and those decreases were contributed by stearic, oleic and arachidonic acids. In the superior and middle temporal gyri and ce rebellum of AD subjects, no significant decreases were found in PC-, P E- and PI-derived fatty acids. The decrease of PE and PI, which are ri ch in oxidizable arachidonic and docosahexaenoic acids, but not of PC, which contains lesser amounts of these fatty acids, suggests a role f or oxidative stress in the increased degradation of brain phospholipid s in AD.