Assessment of Arachidonic Acid Distribution into Phospholipids of Inflammatory Cells

Arachidonic acid located at the sn-2 position of glycerophospholipids is a precursor of an important class of lipid mediators termed eicosanoids (1 ,2 ). The major eicosanoids include leukotrienes, prostaglandins, and thromboxanes. In inflammatory cells, the bulk of AA is esterified into phospholipids (PE, PC, and PI/PS). Arachidonate is further localized in specific subclasses based on different sn-1 substituents of the glycerol backbone of PC and PE. In mast cells and neutrophils, the major subclasses of PC are 1-acyl- and 1-alkyl-linked, whereas 1-acyl- and 1-alk-1-enyl-linked subclasses constitute the bulk of arachidonate in PE (3 –5 ). PI is composed mainly of 1-acyl-linked species in these cells.