Julie Gardener
New Member
Enzymatic synthesis of anandamide, an endogenous ligand for the cannabinoid receptor, by brain membranes
WILLIAM A. DEVANE AND JULIUS AXELRODProc. Natl. Acad. Sci. USA
Vol. 91, pp. 6698-6701, July 1994
Neurobiology
Abstract
Anandamide, an endogenous eicosanold derivative ( il e ), binds to the cannabinoid receptor, a member of the G protein-coupled superfamily. It also inhibits both adenylate cyclase and N-type calcinm channel opening. The enzymatic synthesis of anadamide in bovine brain tissue was examined by incubating brain membranes with [14CJethanolamine and arachidonic acid. Following incubation and extraction into toluene, a radioactive product was identified which had the same Rf value as authentic anandamide in several thin-layer chromatographic systems. When structurally similar fatty acid substrates were compared, arachidonic acid exhibited the lowest ECSO and the highest activity for enzymatic formation of the corresponding ethanolamides. The concentration-response curve of arachidonic acid exhibited a steep slope, and at higher concentrations arachidonate inhibited enzymatic activity. When brain homogenates were separated into subcellular fractions by sucrose density gradient centrifugation, ananmide synthase activity was highst in fractions enriched in synaptic vesicles, myelin, and
microsomal and synaptosomal membranes. When several areas of brain were examined, aanamide synt activity was found to be highest in the hippocanpus, followed by the thalamus, cortex, and striatum, and lowest in the cerebellum,
pons, and medulla. The ability of brain tissue to enzymatically synthesize anandainide and the existence of specific receptors for this eicosanoid suggest the presence of anandamidecontaining (adaergic) neurons.
Source with Charts and Graphs: Enzymatic synthesis of anandamide, an endogenous ligand for the cannabinoid receptor, by brain membranes
