The major degradative pathway of anandamide, an endogenous ligand for cannabinoid receptors, is its enzymatic hydrolysis to arachidonic acid and ethanolamine.1The enzyme responsible for this reaction has been referred to as anandamide amidohydrolase23or fatty acid amide hydrolase.4‘N-Acylethanolamine amidohydrolase’ reported much earlier by Schmid and co-workers5is probably identical to this enzyme.