Anandamide hydroxylation by brain lipoxygenase:metabolite structures and potencies at the cannabinoid receptor.
Anandamide (arachidonyl ethanolamide) is a compound that was identified from porcine brain lipids by its ability to bind to the brain cannabinoid receptor. This study assessed anandamide as a substrate for a brain lipoxygenase and characterised the brain metabolite 12-hydroxyanandamide. Anandamide was also compared with arachidonic acid as a lipoxygenase substrate by examining enzyme kinetics in the presence of either of the two compounds. In addition, a non-mammalian enzyme was used to generate 11- and 15-hydroxy-anandamide in order to compare the cannabinomimetic properties of a range of anandamide derivatives. A ligand displacement assay indicated a large variation in the affinity of anandamide metabolites for the brain cannabinoid receptor. The brain metabolite, 12-hydroxyanandamide had an affinity twice that of anandamide, although the 11- and 15- hydroxy-metabolites were considerably poorer ligands of this receptor. Consistent with the receptor binding data, 12-hydroxyanandamide (unlike 15-hydroxyanandamide) inhibited forskolin-stimulated cAMP synthesis, indicating it to be a functional agonist at the brain cannabinoid receptor. Pharmacological studies of the capacity of anandamide and its metabolites to inhibit the murine vas deferens twitch response indicated the 12-hydroxy-metabolite to be less active than the parent compound, but a better cannabinomimetic than 15-hydroxyanandamide.
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism* / Q000494:pharmacology; D001921:Brain / Q000201:enzymology*; D002186:Cannabinoids / Q000378:metabolism* / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis; D063388:Endocannabinoids; D006900:Hydroxylation; D007700:Kinetics; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D053284:Polyunsaturated Alkamides; D051381:Rats; D017207:Rats, Sprague-Dawley; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug / Q000378:metabolism*; D013379:Substrate Specificity; D014649:Vas Deferens / Q000187:drug effects / Q000502:physiology
D001095:Arachidonic Acids; D002186:Cannabinoids; D063388:Endocannabinoids; D053284:Polyunsaturated Alkamides; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug; D005576:Colforsin; D016718:Arachidonic Acid; D000242:Cyclic AMP; C078814:anandamide