Intestinal absorption and biliary secretion of 5MTHF: effect of ethanol

The aim of this work was to study intestinal absorption, using the whole intestine in vivo with 5-methyltetrahydrofolate (5MTHF), and the subsequent appearance of this compound in the bile, in control and in ethanol-fed rats. The ethanol-fed rats drank ethanol (5 to 30% vol/vol) in tap water for 5 wk. A consumption of 30% was maintained in this group for 20 additional weeks. The two groups of rats were cannulated at the beginning and at the end of the intestine. Three solutions containing 0.5, 1.0, and 2.5 microM of cold 5MTHF and 14C-methyltetrahydrofolic acid (0.01 microCi/mL) in each were perfused throughout the intestine at a flow rate of 4.5 mL/min. The absorption of folate was calculated from the difference between concentrations at the beginning and at the end of the perfusion. A decrease in 5MTHF uptake was observed at the concentration of 1.0 microM (p<0.05): however, folate absorption was not significantly modified at 0.5 and 2.5 microM in the perfusate. Serum folate levels were significantly lower in the ethanol-fed rat group. This fact could be due to a lower intake of folate in the diet and/or to the effect of alcohol on the intestinal absorption. The bile duct was isolated and cannulated with a polyethylene cathether. No significant differences were noted in the biliary folates between the control and the ethanol-fed rats.