Effect of acute ethanol ingestion on integrated plasma prolactin levels in normal men.

Healthy male subjects ingested 1.0 g ethanol/kg (Alcohol Day) and caloric equivalents of sucrose (Control Day). Plasma prolactin was determined on samples collected at 20-min intervals by serial constant blood exfusion, from 2 hr before to 4 hr after the drink. In 14 of the 15 men studied, plasma prolactin levels during the 2-hr period after alcohol administration were elevated an average of 31% above values for the preceding 2-hr period. Data pooled for all subjects revealed a small but statistically significant increase in prolactin coinciding with ascending and peak concentrations of blood alcohol. A significant increment in prolactin was associated with peak blood alcohol levels when values were compared between control and alcohol treatment days. Although of statistical significance, these transient and variable increases were within the normal range of basal prolactin levels for most subjects and are unlikely to be physiologically meaningful.