Or. Velasquez et al., DEVELOPING INTESTINE IS INJURED DURING ABSORPTION OF OLEIC-ACID BUT NOT ITS ETHYL-ESTER, The Journal of clinical investigation, 93(2), 1994, pp. 479-485
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.