Alterations of selected enzymes of phospholipid metabolism in Alzheimer's disease brain tissue as compared to non-Alzheimer's demented controls.

Previous studies have demonstrated elevated brain levels of phosphomonoesters in early stages of Alzheimer's disease and elevations of phosphodiesters later in the disease. In addition, preliminary quantitative analyses of the phospholipids of Alzheimer's brain reveals either decreases in some phospholipids or elevations followed by decreases in others. This study quantitated the activities of selected enzymes involved in phospholipid and choline metabolism and demonstrated elevated glycerol-3-phosphorylcholine phosphodiesterase and decreased choline kinase activities in Alzheimer's disease brain. The former could provide an enzymatic mechanism for the increased phosphorylcholine found in Alzheimer's disease brain.