DEVELOPING INTESTINE IS INJURED DURING ABSORPTION OF OLEIC-ACID BUT NOT ITS ETHYL-ESTER

Although lipids are essential nutrients in the mammalian diet, we have shown that fatty acids are injurious to epithelial cells of developin g piglet intestine during luminal perfusion. Furthermore, the intestin e of young animals sustains greater injury than that of older piglets. In an effort to understand the mechanism for this developmental injur y, we investigated whether changes in the chemical configuration of ol eic acid would alter this damage. Mucosal permeability, as quantitated by the plasma-to-lumen clearance of (51)chromium EDTA, was evaluated during luminal perfusion with oleic acid as compared with its ethyl (e thyl oleate) and glyceryl (glycerol-1-mono-oleate) esters, solubilized with taurocholic acid, in jejunum of 1-d-, 3-d-, 2-wk-, and 1-mo-old piglets. (51)Chromium EDTA clearance increased significantly during ol eic acid and glycerol-1-mono-oleate perfusion, but did not increase du ring perfusion with ethyl oleate or saline. This result was not second ary to failure of absorption of ethyl oleate, as [C-14]oleic acid and ethyl [1(-14)C]oleate were absorbed to a similar extent. Furthermore, developing intestine was able to remove the ethyl group and then re-es terify the fatty acid to form triacylglycerol. These studies indicate that oleic acid-induced mucosal injury can be abolished when the carbo xylic group of the fatty acid is esterified with an ethyl, but not a g lycerol, group. Since the ethyl ester is also absorbed and metabolized similarly to the free fatty acid, this may provide a means of supplyi ng long-chain fatty acids to developing intestine without causing muco sal damage.