Journal of Lipid Research, Vol 25, 129-134, Copyright © 1984 by Lipid Research, Inc.
Does essential fatty acid absorption change with aging?
D Hollander, VD Dadufalza and EG Sletten
Linoleic acid, an essential fatty acid, is a prostaglandin precursor. We
investigated the maximal capacity of the proximal jejunum and distal ileum
to absorb linoleic acid in the unanesthetized rat. Groups of rats 1, 3, 12,
and 28 months of age were studied. As the rats aged, their maximal capacity
to absorb linoleic acid increased fivefold both in the jejunum and ileum.
Since the intestinal wall content of linoleic acid remained relatively
constant, age-related changes in mucosal surface area could not account for
our observations. A decrease in the unstirred water layer thickness with
aging was detected by measuring potential difference changes across the
bowel. The total surface area of the unstirred water layer increased some
fourfold and its resistance to linoleic acid transfer decreased fivefold
with aging. These changes in the dimensions and characteristics of the
unstirred water layer with aging may account for the fivefold increase in
the maximal capacity of the small bowel to absorb linoleic acid.