Previous studies have used the ghrelin receptor antagonists, BIM28163 and JMV2959, to demonstrate the effects of ghrelin antagonism on alcohol intake (Jerlhag et al., 2009b). Our first experiment tested whether the ghrelin receptor antagonist D-Lys3-GHRP-6 has an effect on alcohol preference. Mice were given access to water or 15 % ethanol for 2 h on days 4 to 6, 30 minutes after a saline injection. On day 7, the animals were administered either saline or the antagonist and allowed to drink either water or 15 % ethanol for 4 h, 30 minutes after the injection. Preference to ethanol is shown in Fig. 1A. Mice showed no difference in preference for ethanol over the first three experimental days. Ethanol was clearly preferred: preference on day 4 was 0.57 ± 0.04, on day 5 was 0.70 ± 0.04 and day 6 was 0.68 ± 0.04. On day 4, injection of D-Lys3-GHRP-6 blocked preference to ethanol (0.49 ± 0.06) [F(1,10) = 6.79, p = 0.026). Ethanol intakes also did not change over the first three experimental days. Intake on day 4 was 2.92
