Pharmacokinetic study of ethanol and its metabolites in culture cells

We examined the disposition of ethanol, acetaldehyde and acetate in culture cells. Rat hepatoma-derived cells, H4IIE, were grown in T-shaped flasks to confluence in minimal essential medium supplemented with 5% fetal bovine serum. For the experimental group, the medium in the flask was replaced with a medium containing a 0, 4, 8 or 20 mM ethanol solution. For the control group, cell-free flasks containing media of the same ethanol concentrations were used. The ethanol, acetaldehyde and acetate concentrations in the flask were measured periodically by headspace gas chromatography. We found that the ethanol concentration of the medium decreased in both the control and the experimental groups; however, the rate of ethanol disappearance differed between these two groups, suggesting that ethanol is metabolized in the culture cells, and that its metabolism is saturated at a lower concentration. The acetaldehyde level was usually markedly low. Acetate was produced both with and without ethanol treatment, but the rate of acetate production increased with ethanol treatment, indicating that a certain percentage of acetate leaks into the medium. These findings suggest that ethanol in culture cells behaves in a kinetic fashion in vivo.