THE RELATIONSHIP OF ETHANOL FEEDING TO THE METHYL FOLATE TRAP

Feeding rats a semiliquid ethanol diet for a period of four weeks produced a hepatic accumulation of the methylating agent N-5-methyltetrahydrofolate ((NCH3THF)-C-5). When the ethanol-containing diet was supplemented with 0.5% betaine, an agent known to promote the generation of methionine and S-adenosylmethionine (SAM) in ethanol-fed animals, the accumulation of (NCH3THF)-C-5 was prevented. One index that the methyl folate trap exists is the hepatic accumulation of (NCH3THF)-C-5, and a second index is that the (NCH3THF)-C-5 accumulation can be relieved by methionine administration. Since ethanol is shown to produce (NCH3THF)-C-5 accumulation in this study, and since betaine (a generator of methionine and SAM) acts to eliminate this accumulation, it is suggestive that ethanol can contribute to the impairing hepatic condition referred to as the ''methyl folate trap.''