Effect of ethanol exposure on Xenopus embryo lipid composition

Exposure to ethanol is known to alter cell membranes both chemically and bi ophysically; these effects may be related to the development of tolerance a nd physical dependence. In the present study, the effects of various concen trations of ethanol (1-250 mM) on the lipid composition after the first 6 d ays of Xenopus embryo development were investigated, using an in vitro fert ilization technique. Lipid analysis revealed: (1) a decrease of the cholest erol/phospholipid molar ratio mainly derived from a higher content of phosp holipids; (2) an increase of phospholipid unsaturated fatty acids, especial ly C20:4 and C20:5, with ethanol concentration of 150-250 mM; (3) a decreas e of lipid-bound sialic acid with ethanol concentrations of greater than or equal to5 mM. These results underline that sialoglycoconjugates are a more sensitive target of alcohol in comparison with other lipid components. The cultured embryo method certainly represents a useful model for investigati on of the direct effects of ethanol on lipid metabolism, excluding maternal interference which can lead to misinterpretation of data.