FATTY-ACID ETHYL-ESTER SYNTHESIS BY HUMAN LIVER-MICROSOMES

Fatty acid ethyl eaters are a family of non-oxidative metabolites of e thanol present in many tissues after ethanol consumption. In this repo rt we demonstrate the existence in human liver of an acyl-CoA:ethanol acyltransferase activity which may be responsible in part for the synt hesis of these compounds in vivo. The effects of oleoyl-CoA and ethano l concentrations, presence or absence of bovine serum albumin and dete rgent, pH and enzyme concentration on this activity have been determin ed. Acyl-CoA:ethanol acyltransferase activity is localised in the memb rane-bound fraction. Using inhibitors directed against related enzyme activities, it has been shown that the activity is not related to seri ne-dependent carboxylesterases or acyl-CoA:cholesterol acyltransferase , but that it may be associated with acyl-CoA hydrolase activity. We h ave also compared acyl-CoA:ethanol acyltransferase activity with fatty acid ethyl ester synthase activity in microsomes and cytosol from the same liver. Our data indicate that these activities an comparable in vitro (on a units/g liver basis), and suggest that both may be signifi cant in vivo.