COMPARATIVE EFFECTS OF INTESTINAL-ABSORPTION OF FOLIC-ACID AND METHYLTETRAHYDROFOLIC ACID IN CHRONIC ETHANOL-FED RATS

This study concerns in vivo folic acid and methyltetrahydrofolic acid (MTHF) absorption by the whole intestinal surface after 20 weeks of 30% ethanol ingestion in drinking water. The results were compared with control rats fed ad libitum. The total intestinal serosal areas were similar in ethanol-fed and control rats. Significant increases in intestinal length, and decreases in tissue wet and dry weights were found in ethanol-fed rats. Serum folic acid concentrations were significantly less in the animals which had ingested ethanol than in the control rats. Intestinal folic acid absorption was significantly increased at lower substrate concentrations (0.5 and 1 mu M), while no difference was observed at 2.5 mu M in the ethanol-fed rats. Folic acid absorption relative to tissue wet weight showed significant increases at all tested concentrations in the ethanol-fed rats. Intestinal MTHF absorption showed no significant changes at 0.5 mu M MTHF concentration, and an increase was observed in the absorption values at 1 and 2.5 mu M concentrations in the ethanol-fed rats. When expressed as tissue wet weight, MTHF absorption values in ethanol-fed rats increased at 1 and 2.5 mu M but did not differ at 0.5 mu M substrate concentrations. The above results indicate compensatory responses in the folic acid and MTHF intestinal absorption after chronic ethanol ingestion. These effects are observed when the whole intestinal surface is evaluated.