Moreover, while several reports suggested that alcohol in mice in the 24 hour access procedure is in part consumed (like food) for its caloric value (Dole and Gentry, 1985; McMillen and Williams, 1998), this does not appear to be the motivation for alcohol consumption in the DID paradigm. Data collected by Lyons et al. (2008) showing that systemic ghrelin administration, known to promote food consumption, does not increase alcohol intake in the DID procedure in food-deprived mice. An earlier study carried out by Sparrow et al. (2007), where mice given access to food during ethanol consumption drank significantly more than mice that did not have food available during access to ethanol, also disputes the hypothesis that the excessive alcohol intakes in DID procedures are due to caloric need. Thus, while a detailed understanding of the specificity of the effect of ghrelin receptor antagonist on alcohol intake would benefit from further studies, the data accumulated so far point to independence of the effects of ghrelin receptor antagonists on alcohol intake from effects of these drugs on food consumption.
