Determination of Plasmalogen-Selective Phospholipase A2 Activity by Radiochemical and Fluorometric Assay Procedures

Plasmalogens are a unique class of glycerophospholipids (1 ) characterized by the presence of a vinyl ether substituent at the sn-1 position of the glycerol backbone. Found in all mammalian cells, these phospholipids are especially abundant in brain and heart (1 ). However, while choline plasmalogen is enriched in heart tissue, brain tissue is rich in ethanolamine plasmalogen. Despite their ubiquitous distribution, little is known about their role in mammalian metabolism. These lipids may act as a reservoir for arachidonic acid, the precursor for prostaglandins and thromboxanes. The vinyl ether linkage of plasmalogen may also play an important role in protecting cellular membranes against oxidative stresses (2 ,3 ). The breakdown of plasmalogen may be a receptor-mediated process related to signal transduction (4 ,5 ).