Influence of fatty alcohol and other fatty acid derivatives on fatty acid uptake into rat intestinal epithelial cells

We investigated the influence of various substrates on the uptake of long-c hain fatty acid into IEC-6, rat intestinal epithelial cell line. The uptake of [H-3]oleic acid into IEC-6 cells was a saturable function of the oleic acid concentration. Long-chain fatty acids significantly inhibited the olei c acid uptake into IEC-6 cells and shorter-chain fatty acids had little or no effect. Various fatty acid esters suppressed the oleic acid uptake into IEC-6. Fatty alcohols also inhibited oleic acid uptake into IEC-6 and the l ength of the carbon chain played an important role. These results suggest t hat long-chain fatty acid uptake was inhibited by the substrates which had a structure similar to long-chain fatty acids, especially those with a long carbon chain. At least two molecules, fatty acid translocase and fatty aci d transport protein type 4, which are considered to be involved in the long -chain fatty acid transport into the cell, were expressed on IEC-6 cells, s upporting the existence of the carrier-mediated system of long-chain fatty acid transport on IEC-6 cells.