MEMBRANE PHOSPHOLIPID ALTERATIONS IN ALZHEIMERS-DISEASE - DEFICIENCY OF ETHANOLAMINE PLASMALOGENS

The ethanolamine plasmalogens are decreased whereas serine glycerophos pholipids are significantly increased in plasma membrane phospholipid in affected regions of brain in Alzheimer's disease. This may be due t o stimulation of Ca2+-independent plasmalogen-selective phospholipase A(2), which was recently discovered in brain. This phospholipase A(2) differs from other Ca2+-independent phospholipases A(2) in response to ATP and various inhibitors. It may be responsible for excess release of arachidonic acid and accumulation of prostaglandins and lipid perox ides in AD. Accumulation of the above lipid metabolites due to abnorma l receptor function and signal transduction may contribute to neurodeg eneration in AD.