Previous studies have demonstrated that a moderate dose of ethanol induced a significant increase in the plasma β-endorphin content of subjects from families with a history of alcoholism (high risk [HR]), but not of subjects from families without a history of alcoholism (low risk [LR). The objective of this study was to examine the response of the pituitary β-endorphin and adrenal cortisol systems to various concentrations of ethanol in male and female subjects at high and low risk of the future development of alcoholism.
All subjects participated in four experimental sessions. In each session the subjects were given a drink containing one of the following doses of ethanol: O, 0.25, 0.50, and 0.75 g of ethanol per kilogram of body weight (for a 60- to 70-kg individual). Blood samples were taken at 0 minutes and at 15, 45, 120, and 180 minutes after the drink for estimation of the blood alcohol, plasma β-endorphin, and plasma cortisol levels.
The concentration of alcohol in the blood at various intervals after the drink was similar among the subjects, regardless of the risk group. Ethanol increased the plasma level of β-endorphin-related peptides of the HR but not of the LR subjects in a dose-dependent manner. All subjects showed a small decrease in plasma cortisol level with time, but ethanol ingestion did not significantly alter the plasma cortisol levels.
This study indicates that the pituitary β-endorphin system, but not the adrenal cortisol system, of the HR subjects shows an enhanced sensitivity to ethanol, which may be an important factor in controlling ethanol consumption.