Anandamide and AM251, via water, modulate food intake at central and peripheral level in fish.
The endocannabinoid system is a major regulator of food intake in many animal species. Studies conducted so far have mostly focused on mammals, and, therefore, in this study, the role of the endocannabinoid system in food intake in the sea bream Sparus aurata was investigated. The effect of different doses of the endocannabinoid anandamide (AEA), administered via water, was evaluated after different exposure times (30, 60 and 120 min) at both physiological and molecular levels. The results obtained indicate that fish exposed to AEA via water present approximately 1000-fold higher levels of AEA in both the brain and liver, which correlated with a significant increase in food intake and with the elevation of cannabinoid receptor 1 (CB(1)) and neuropeptide Y (NPY) mRNA levels in the brain. A peripheral effect of AEA was also observed, since a time-dependent increase in hepatic CB(1) mRNA and protein levels was detected. These effects were attenuated by the administration, again via water, of a selective cannabinoid CB(1) receptor antagonist (AM251). These findings indicate that the endocannabinoid AEA, at doses that stimulate food intake in fish, concomitantly stimulates the expression of the orexigenic peptide NPY as well that of its own receptor, thereby potentially enhancing its effect on food consumption. In agreement with a role of AEA in food intake in S. aurata, we found increased brain levels of both this and the other endocannabinoid, 2-arachidonoylglycerol (2-AG), following food deprivation.
Department of Marine Science, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy.
Chiara Carla
CC
Piccinetti
Beatrice
B
Migliarini
Stefania
S
Petrosino
Vincenzo
V
Di Marzo
Oliana
O
Carnevali
D000818:Animals; D001095:Arachidonic Acids / Q000008:administration & dosage* / Q000032:analysis; D001923:Brain Chemistry; D063385:Cannabinoid Receptor Modulators / Q000008:administration & dosage* / Q000032:analysis; D004435:Eating / Q000187:drug effects*; D063388:Endocannabinoids; D005508:Food Deprivation / Q000502:physiology; D005989:Glycerides / Q000032:analysis; D008099:Liver / Q000737:chemistry; D009478:Neuropeptide Y / Q000235:genetics; D010880:Piperidines / Q000008:administration & dosage*; D053284:Polyunsaturated Alkamides / Q000008:administration & dosage* / Q000032:analysis; D011720:Pyrazoles / Q000008:administration & dosage*; D012333:RNA, Messenger / Q000032:analysis; D043884:Receptor, Cannabinoid, CB1 / Q000032:analysis / Q000037:antagonists & inhibitors* / Q000235:genetics; D021541:Sea Bream / Q000502:physiology*; D014867:Water / Q000008:administration & dosage
D001095:Arachidonic Acids; D063385:Cannabinoid Receptor Modulators; C543264:Cnr1 protein, rat; D063388:Endocannabinoids; D005989:Glycerides; D009478:Neuropeptide Y; D010880:Piperidines; D053284:Polyunsaturated Alkamides; D011720:Pyrazoles; D012333:RNA, Messenger; D043884:Receptor, Cannabinoid, CB1; D014867:Water; C103505:AM 251; C094503:glyceryl 2-arachidonate; C078814:anandamide