Anandamide modulates growth and lipid metabolism in the zebrafish Danio rerio

Endocannabinoids are known to be lipidic mediators with several biological functions as the stimulation of food intake and lipid metabolism via cannabinoid receptor CB1. Many evidences, such as the presence of CB1 mRNA in fat tissue, suggest a peripheral role for endocannabinoids in regulating lipogenesis and body weight in mammals.As animal models constitute good tools to study endocannabinoid system dynamics, we analyzed the role of the endocannabinoid anandamide (AEA) in modulating lipid metabolism and growth in zebrafish larvae and adults.The data obtained indicated that AEA administered via water modulates the transcription of its own receptor CB1, besides to up-regulate gene expression of sterol regulatory element binding protein (SREBP) and of the insulin-like growth factors (IGF-1 and IGF-2).The results here obtained represent the first evidence in fish of the endocannabinoid system involvement in lipid metabolism and growth.