Ethanol acceptance as a function of genotype amounts of brain [Met]enkephalin

Our results indicate a negative correlation between the amount of ethanol (10%) consumed and endogenous levels of brain [Met]enkephalin in C57BL/6J (alcohol-preferring) and DBA/2J (alcohol-nonpreferring) inbred mice strains. Additionally, it was found that 8 wk after 1-day starved groups of both C57BL/6J and DBA/2J mice were challenged with ethanol (10%) for 1-day acceptance, they had significantly lower levels of brain [Met]enkephalin compared with their nonalcohol-treated controls. These results suggest that the brain endogenous peptidyl opiates may play a crucial role in alcohol-seeking behavior.