Effects of acute and chronic ethanol exposure on fatty acid ethyl ester synthases in mouse cerebellar membranes

Fatty acid ethyl esters (FAEE), the products of esterification of fatty acids with ethanol (EtOH), are shown to cause organ injury in chronic alcohol abusers. Their formation is catalysed by the enzyme FAEE synthase which is present in both animal and human brain. In the present study, we investigated the effects of acute and chronic EtOH exposure on FAEE synthase activity in crude cerebellar membrane preparation of mice, using oleic, linoleic and arachidonic acids as substrates. The results indicate that FAEE synthase activity exists in synaptosomal membranes and the activity of this enzyme varied with various fatty acid substrates. The synthase activity was optimal in the membranes from the animals exposed acutely to EtOH when oleic acid was used as a substrate. A 14% increase in the incorporation of oleic acid was observed in the membranes from animals exposed to acute dose of EtOH. However, there was a 10% reduction in the synthase activity when arachidonic acid was used as a substrate in the membrane preparations from mice exposed chronically to EtOH. The results suggest that substrate specificity for FAEE synthase varied with the duration of exposure to EtOH.