Protein synthesis in rat intestine in vitro: the acute effect of ethanol

We studied the rate of 3H-leucine incorporation and the acute effect of ethanol on rat jejunum employing a newly-developed method originally for determining rapid solute uptake in vitro. 3H-leucine incorporation was linear up to 12 min and significantly inhibited by 10 microM of cycloheximide, a specific inhibitor for protein synthesis. The inhibition was 86% at 100 microM indicating that the rate of 3H-leucine incorporation was a good index for protein synthetic activity in the intestinal cells. Incorporation was not changed significantly by 8% dilution (with water) but was inhibited by 8% ethanol to less than 1/4 of the control level. Lower concentrations of ethanol had no consistent effects. The action of ethanol was rapid, independent of the precursor level, and was not readily reversible. Although the nature of ethanol's action was not clear, sucrose, in a dose-dependent manner, also significantly inhibited incorporation rapidly, indicated that the action of media hyperosmolality could not be eliminated as part of the cause of inhibition induced by ethanol.