The prostaglandin pathway. Synthesis of prostanoids by the COX enzymes following the catalytic release of arachidonic acid from membrane phospholipids by calcium-dependent phospholipase A2. PGH2 is metabolized as indicated by specific synthases. Alternatively, arachidonic acid can be metabolized by lipoxygenase or cytochrome P450 activities to leukotrienes, lipoxins, and hyroxyl/epoxyeicosatetraenoic fatty acids. Reproduced from (67).