FIGURE 1

(a) Schematic representation of the roles of FAAH, MGL and COX-2 in the metabolism of AEA, 2-AG and the related N-acylethanolamines OEA and PEA. The endocannabinoids are poor substrates for COX-1 compared to COX-2, at least in cell-free systems. Further metabolism of the oleic acid (OA), palmitic acid (PA) and AA has not been shown in the figure, for reasons of simplicity. (b) Structures of AEA, 2-OG and representative COX-2 metabolites (PGE₂-EA and PGE₂-GE). 2-AG, 2-arachidonoylglycerol; AA, arachidonic acid; AEA, anandamide; COX, cyclooxygenase; FAAH, fatty acid amide hydrolase; MGL, monoacylglycerol lipase; OA, oleic acid; OEA, oleoylethanolamide; PA, palmitic acid; PEA, palmitoylethanolamide; PG-EA, prostaglandin ethanolamides ('prostamides'); PG-GE, prostaglandin glyceryl esters.