title: Cold exposure stimulates synthesis of the bioactive lipid oleoylethanolamide in rat adipose tissue.
abstract: Oleoylethanolamide (OEA) is an endogenous lipid mediator that inhibits feeding and stimulates lipolysis by activating the nuclear receptor peroxisome proliferator-activating receptor-alpha. Little is known about the physiological regulation of this compound outside of the gastrointestinal tract, where its production is regulated by feeding. Here we show that cold exposure increases OEA levels in rat white adipose tissue but not in liver or intestine. This change is accompanied by parallel elevations in the activity of N-acyltransferase, a key enzyme responsible for OEA synthesis, without concomitant changes in fatty acid amide hydrolase, an enzyme responsible for OEA degradation. Moreover, cold stimulates the production of two species of N-oleoylphosphatidylethanolamine OEA precursors. The changes in OEA biosynthesis are reversed by pretreatment with the beta-receptor antagonist propranolol, suggesting a role for beta-adrenoreceptors in this response. In agreement with these findings, the beta-agonists noradrenaline and isoproterenol stimulate OEA production in isolated adipocytes, an effect that is mimicked by the adenylyl cyclase activator forskolin. Collectively, these results identify cold exposure as a natural stimulus for OEA formation in white fat and suggest a role for the sympathetic nervous system in regulating OEA biosynthesis.
authors.affiliation: Center for Drug Discovery, and Department of Pharmacology, University of California, Irvine, California 92697, USA.
authors.forename: Jesse
authors.initials: J
authors.lastname: LoVerme
authors.forename: Manuel
authors.initials: M
authors.lastname: Guzmán
authors.forename: Silvana
authors.initials: S
authors.lastname: Gaetani
authors.forename: Daniele
authors.initials: D
authors.lastname: Piomelli
mesh_terms: D000217:Acyltransferases / Q000378:metabolism; D017667:Adipocytes / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D003080:Cold Temperature; D005576:Colforsin / Q000494:pharmacology; D063388:Endocannabinoids; D004822:Epididymis / Q000378:metabolism; D007545:Isoproterenol / Q000378:metabolism; D050356:Lipid Metabolism; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D009829:Oleic Acids / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000378:metabolism
chemical_list: D063388:Endocannabinoids; D009829:Oleic Acids; D011943:Receptors, Adrenergic, beta; D005576:Colforsin; C488250:oleoylethanolamide; D000217:Acyltransferases; D007545:Isoproterenol; D009638:Norepinephrine