MONTREAL, March 20 (UPI) -- A study of rodents confirmed that low-to-moderate levels of alcohol alter beta-endorphins producing a general feeling of well-being, Canadian researchers said.
Corresponding author Christina Gianoulakis of McGill University in Montreal said alcohol may increase or decrease the release and the synthesis of endogenous opioid peptides -- endorphins released during excitement, pain and orgasm -- in distinct brain regions important for drug addiction.
"Some of the functions of opioid peptides are similar to those of the opiate morphine," Gianoulakis said in a statement. "Like morphine, endogenous opioid peptides can induce analgesia and a mild euphoric effect, reduce anxiety and may lead to a general feeling of well being."
Therefore, increased release of endogenous opioid peptides in response to drinking could be partially responsible for the mild euphoric and anxiolytic effects associated with low-to-moderate amounts of alcoholic beverages, Gianoulakis said.
The researchers injected male rats with either saline or alcohol of varying amounts and tracked the response of endorphins, enkephalins and dynorphins at the level of the midbrain.
The study, to be published in the June issue of Alcoholism: Clinical & Experimental Research, found that low-to-moderate but not high doses of alcohol increase the release of beta-endorphins in one of the brain regions shown to be important for mediating the rewarding effect of alcohol.
High doses of alcohol are known to induce sedative and hypnotic effects and often increase, rather than decrease, anxiety, the study said.