Beta-endorphin mediates behavioral despair and the effect of ethanol on the tail suspension test in mice.

Background: The opioid peptide beta-endorphin (beta-E) is synthesized and released in response to stressful stimuli as well as acute alcohol administration. The release of beta-E following exposure to an inescapable aversive situation may mediate behaviors that contribute to allostasis of the stress response. The present study examines the effects of beta-E on immobility in assays involving inescapable stress, both under basal conditions and after acute administration of EtOH.