Ethyl alcohol enhances plasminogen activator secretion by endothelial cells.

Confluent cultures of cloned bovine endothelial cells, which were derived from large vessels, produced and secreted plasminogen activator (PA) at constant rates. Exposure of these cultures to increasing concentrations of ethyl alcohol resulted in a significant augmentation of PA production and secretion. This effect, which was observed after three hours and was maximal after 18 hours of incubation, was abolished by simultaneous exposure of the cultures to cycloheximide, indicating that active protein synthesis was necessary for the observed increase of PA activity. Other aliphatic alcohols such as propanol and butanol also significantly augmented PA production and secretion by endothelial cells, whereas acetaldehyde and acetylcoenzyme A, known metabolites of ethyl alcohol, had no stimulatory effect on protease secretion by the cells. Therefore, the alcohol itself rather than its metabolites was responsible for the enhancement of PA secretion by endothelial cells. These in vitro studies may explain the increased fibrinolytic activity found in the plasma of persons consuming moderate amounts of alcohol.