Identification of fatty acid ethyl esters as products of rabbit myocardial ethanol metabolism

Abstract

To characterize metabolic factors potentially associated with alcohol-induced heart disease, myocardial ethanol intermediary metabolism was studied in isolated, perfused rabbit hearts and whole heart homogenates. Results showed that intact rabbit hearts and homogenates of rabbit left ventricle incorporate carbon-14-labeled ethanol at 20 and 59 nmol/g/h, respectively, into a neutral lipid species that co-migrates with triacylglycerides in standard chromatographic solvent systems. After isolation and purification by thin layer chromatography in an apolar solvent system, the labeled species were identified by gas chromatographic-mass spectral analysis to be a family of fatty acid ethyl esters. Heat inactivation of incorporation and the kinetics of formation of products suggest that the process is enzymatic. Gas chromatography identified the fatty acid components as predominantly unsaturated moieties, especially oleic, linoleic, and arachidonic acids. These results provide insight into potential biochemical mechanisms contributing to the triacylglyceride accumulation, decreased beta oxidation of fatty acids, and other lipid abnormalities typical of effects of ethanol on the heart.