Eicosanoid Synthesis (Prostaglandins & Leukotrienes)
Arachidonic acid-derived lipid mediators regulating inflammation and vascular tone.
Overview
Arachidonic acid (AA) is released from membrane phospholipids by phospholipase A2 (PLA2). The cyclooxygenase (COX) pathway converts AA to prostaglandins (PGE2, PGI2, PGF2α, PGD2) and thromboxane A2 (TXA2). The lipoxygenase (LOX) pathway produces leukotrienes (LTB4, LTC4/D4/E4) and lipoxins. The cytochrome P450 pathway generates EETs and 20-HETE. Each class has distinct receptors and biological effects on inflammation, pain, fever, platelet aggregation, and vascular tone.
Cellular Location
Cell membranes → cytoplasm → extracellular
Clinical Significance
NSAIDs (aspirin, ibuprofen) inhibit COX; low-dose aspirin prevents cardiovascular events (TXA2 inhibition); leukotriene antagonists (montelukast) treat asthma; COX-2 inhibitors (celecoxib) for inflammation.