Fatty acid ethyl esters, nonoxidative ethanol metabolites, synthesis, uptake, and hydrolysis by human platelets

The consumption of alcohol is known to have both positive and negative effects on the functioning of the cardiovascular system in general, and on platelet function in particular. Fatty acid ethyl esters (FAEEs) are non-oxidative metabolite of ethanol that may mediate the ethanol effect on platelet function leading to either bleeding or clotting. The aim of the current study was to investigate the synthesis, uptake, and hydrolysis of FAEEs by human platelets. Isolated platelets were incubated with ethanol for various times, and FAEE synthesis were measured by gas chromatography mass-spectrometry (GC-MS). In addition, platelets were incubated with 14C-ethyl oleate, and FAEE uptake and hydrolysis were measured. There was significant synthesis of FAEEs by human platelets within 30 min of exposure to ethanol. The major FAEE species formed by human platelets exposed to ethanol were ethyl palmitate and ethyl stearate. FAEE uptake by human platelets showed maximum uptake by 60 s. The majority of FAEEs (50-80%) incorporated into platelets remained intact for up to 10 min. FAEE hydrolysis led to an increase in free fatty acids, with minimal subsequent esterification of the free fatty acids into phospholipids, triglycerides, and cholesterol esters. These studies show that FAEEs, non-oxidative metabolite of ethanol, can be incorporated into, synthesized, and hydrolyzed by human platelets.