The fatty acid amide hydrolase (FAAH), is the enzyme responsible for the hydrolysis of anandamide, an endocannabinoid. FAAH has broad specificity in terms of other substrates, such as oleamide (a sleep factor) and 2-arachidonoyl glycerol (2- AG), but the significance of these activities in vivo remains to be determined. FAAH is a membrane-bound protein localized predominantly in microsomal or mitochondorial fraction of rat brain and rat liver and porcine brain. The FAAH activity was by far the highest in the liver, followed by the small intestine, brain, testis and many other organs, but hardly detectable in skeletal muscle and heart. The presence of FAAH in primary cells and cell lines is not universal.  FAAH activity is not detectable in human epithelioid carcinoma, HeLa, human larynx epiermoid carcinoma, Hep2, human hepatocellular carcinoma, HepG2, or human astrocytoma cells, CCFSTTG1.The enzyme was found in various cell lines such as mouse neuroblastoma, RBL-2H3, J774, MCF-7, EFM-19 and human neuroblastoma CHP199. Its distribution in organs and tissues, and the inhibitors that have been developed for FAAH that may have therapeutic potential.


1.Deutsch DG, et al. Prostaglandins Leukot Essent Fatty Acids. 2002;66(2-3):201–210.