Possible Interrelationship of Ethanol Metabolism and Choline Oxidation in the Liver

Abstract

Since it has been demonstrated that ethanol increases choline uptake in liver, this study was designed to determine whether this is a direct effect of ethanol or a result of ethanol metabolism. This study also sought to determine whether oxidative degradation of choline regulates choline uptake in the liver and if ethanol-induced choline uptake is effected through the action of choline oxidase.Using the isolated perfused-liver technique to study choline uptake, it was found that the addition of pyrazole, an alcohol dehydrogenase inhibitor, to the perfusate completely inhibited the effect of ethanol on choline uptake. This work suggested that ethanol metabolism is necessary to obtain the ethanol effect. Experiments with guinea pig livers, which contain very little choline oxidase, and the use of a choline oxidase inhibitor in rat experiments showed that choline uptake is partially regulated by choline oxidase. The choline oxidase inhibitor was also shown to inhibit the ethanol effect on choline uptake, suggesting that increased choline requirement due to alcohol ingestion may be the result of ethanol metabolism stimulating oxidative degradation of choline.