Turnover of ethyl-linoleate in rat plasma and its distribution in various organs

The fate of [14C]ethyl-linoleate (EthLin) after its intravenous administration was investigated in pentobarbital-anesthetized rats. The disappearance of [14C]EthLin from the plasma was very rapid and followed quite closely a biexponential function of time. Fitting of the experimental data to a two-compartmental mammillary model revealed that the labeled compounds are eliminated from the plasma with a half-life of < 1 min during the early time following the intravenous injection and that a large portion of the EthLin is hydrolyzed instantly to linoleic acid and ethanol. About 9-11% of the plasma [14C]EthLin or its breakdown products are irreversibly cleared from the plasma compartment each minute. Most of the 14C-labeled compounds that originated in the plasma were recovered in the rat liver and lungs and to a lesser extent in the heart, spleen, and kidneys. Two hr after the [14C]EthLin administration, approximately 2.5-5.5% of the total radioactivity in the various organs was still associated with EthLin. Such accumulations, although relatively small, indicate that fatty acid ethyl esters (FAEEs) may be taken up from the plasma. Thus, some of the FAEEs that are formed in certain organs may spillover to the circulating blood where much of it would be hydrolyzed to free fatty acids, but reuptake from the plasma may still account, to some extent, to FAEE-induced damage in chronic alcohol abusers.