Oleylethanolamide (OEA) is a natural analogue of the endogenous cannabinoid anandamide that is suspected to have a role in cellular signaling. But, in 8 November Nature, F. Rodriguez de Fonseca and colleagues from Complutense University, Madrid, Spain and University of California at Irvine, US show that the main role of OEA is as a significant lipid mediator in the peripheral regulation of feeding.

Using rats Rodriguez de Fonseca et al. found that food deprivation markedly reduced OEA biosynthesis in the small intestine while administration of OEA caused a significant decrease in food intake and gain in body mass. This anorexic effect was behaviorally selective and was associated with the discrete activation of brain regions involved in the control of satiety. But, the OEA effect did not occur when the compound was injected directly into the brain or if sensory fibres peripheral to the central nervous system were...