Figure 5.

The typical oxylipin and enzymatically oxidized phospholipid pathway in circulating blood cells. Membrane phospholipids can be cleaved by phospholipase A2 (PLA₂) into polyunsaturated fatty acids (PUFAs), such as arachidonic acid (FA 20:4). These PUFAs are oxygenated via the action of cyclooxygenase (COX) or lipoxygenase (LOX) enzymes to generate oxylipins, which are referred to as ‘eicosanoids’ if generated from 20-carbon PUFAs such as arachidonic acid (AA). Some oxylipins may be re-esterified back to the membrane to form enzymatically oxidized phospholipids. The ‘n-’ prefix denotes the enzyme isoforms which are responsible for generating oxylipin positional isomers at the corresponding ‘n-’ carbon on AA (e.g. 12-LOX in platelets generating 12-hydroxyeicosatetraenoic acids, or 12-HETE). HPETE, hydroperoxyeicosatetraenoic acid; LT, leukotriene.