AJP - Gastrointestinal and Liver Physiology, Vol 253, Issue 6 751-G759, Copyright © 1987 by American Physiological Society
Differential intestinal absorption of two fatty acid isomers: elaidic and oleic acids
A. Bernard, B. Echinard and H. Carlier
Laboratoire de Physiologie de la Nutrition, Ecole Nationale Superieure de Biologie Appliquee a la Nutrition et a l'Alimentation, Campus Universitaire Montmuzard, Dijon, France.
The absorption of 14C-labeled oleic acid and 14C-labeled elaidic acid was
studied in bile- and pancreatic juice-diverted adult rats. In some cases
these acids were compared with 14C-labeled palmitic acid absorption. Sodium
taurocholate-emulsified test infusates containing an equimolar mixture of
monopalmitin and two fatty acids (oleic and elaidic or palmitic), one of
which was 14C labeled, were infused through a duodenal canula. The chyle
was collected from the mesenteric lymphatic vessel by plastic tubing. Among
the three fatty acids studied, oleic acid exhibited the highest lymphatic
recovery rate (43-50%). Elaidic and palmitic acids appeared more slowly and
in lesser amounts (10-17%). Simultaneously, the highest amount of
chylomicrons was observed when the lipid emulsion contained oleic acid
alone; the lowest was observed when elaidic acid was the only unsaturated
fatty acid. Experimental data have also shown that compared with elaidic
acid, oleic acid is preferentially incorporated into the lymph
triglycerides. We can conclude from the data presented that the enterocytic
enzymes involved in the absorption of lipids show a high degree of
specificity related to the fatty acid isomery, since the absorption of
elaidic acid differs markedly from its isomer oleic acid.
