Effect of bombesin on behaviors associated with ethanol satiation and blood ethanol levels.

The behavioral specificity and physiological significance of bombesin-induced inhibition of ethanol intake were assessed in water-deprived rats. The behavioral display accompanying suppression of 5% ethanol intake by bombesin tetradecapeptide (BBS-14, 1-4 micrograms/kg) was measured with an instantaneous time-sampling technique. Blood ethanol levels were measured after peripheral BBS-14 and bombesin nonapeptide (BBS-9) administration, and after either oral self-administration or peripheral injection of ethanol. The display accompanying BBS-14-reduced ethanol consumption differed from control in that less drinking and feeding behaviors were observed and resting increased, dose-dependently. The typical behavioral sequence of ethanol satiation was observed in all conditions. Both BBS-14 and -9 reduced blood ethanol levels when oral intake was suppressed, and BBS-14 did not affect blood ethanol levels or elimination rate when ethanol was injected. The results are compatible with an hypothesis of a functional role for endogenous bombesin-like peptides and receptors in a neuropeptide control of ethanol intake and energy balance.