T. Sugiura et al., N-ARACHIDONOYLETHANOLAMINE (ANANDAMIDE), AN ENDOGENOUS CANNABINOID RECEPTOR-LIGAND, AND RELATED LIPID MOLECULES IN THE NERVOUS TISSUES, Journal of lipid mediators and cell signalling, 14(1-3), 1996, pp. 51-56
The effects of N-arachidonoylethanolamine (anandamide) and related com
pounds on the binding of [H-3]CP55940 to rat brain synaptosomes were e
xamined. Anandamide was shown to inhibit competitively the specific bi
nding of [H-3]CP55940 to synaptosomal membranes. The K-i value was 89
nM. In contrast, N-acylethanolamine containing saturated or monoenoic
fatty acids did not exhibit high binding affinity. Several structural
analogues of anandamide showed some binding activity. Among them, 2-ar
achidonoylglycerol is noteworthy because of its occurrence in mammalia
n tissues. A biosynthetic study indicated that anandamide can be synth
esized via two separate synthetic pathways. The first is synthesis fro
m free arachidonic acid and ethanolamine, and the second is the format
ion of N-arachidonoyl phosphatidylethanolamine (PE) from diarachidonoy
l phospholipids and PE and the subsequent enzymatic release of N-arach
idonoylethanolamine. The latter pathway appears to explain very well t
he fatty acid composition of N-acylethanolamines present in mammalian
tissues.