AJP - Gastrointestinal and Liver Physiology, Vol 270, Issue 2 268-G276, Copyright © 1996 by American Physiological Society
Triacylglycerol and cholesterol transport during absorption of glycerol trioleate vs. glycerol trielaidate
T. J. Kalogeris, L. Gray, Y. Y. Yeh and P. Tso
Department of Physiology, Louisiana State University Medical Center, Shreveport 71130, USA.
We used conscious, chronic lymph-fistula rats to compare intestinal
lymphatic transport of glycerol trioleate (TO) vs. glycerol trielaidate
(TE) and to determine the effect of TO vs. TE on absorption and transport
of cholesterol. Rats were implanted with intestinal lymph fistulas and
duodenal cannulas and then given intraduodenal infusions of lipid emulsions
containing purified TO or TE (40 mumol/h) and cholesterol (7.8 mumol/h + 2
microCi [14C]cholesterol). Lymph samples were collected at 0, 2, 4, 5, 6,
7, and 8 h after the start of lipid infusion. Lymphatic output and luminal
and gut wall recovery of radioactive lipid at 8 h were quantified.
Triacylglycerol (TG) fatty acid isomers did not affect lymphatic output of
TG; lymph TG fatty acid composition and output reflected infusate
composition. Lymphatic output of cholesterol (mass and radioactivity) did
not differ between groups; luminal and gut wall recovery of
[14C]cholesterol was also similar between groups. Similar lymphatic
transport of TG and cholesterol between triolein- and trielaidin-infused
rats was maintained for up to 16 h after the cessation of an infused lipid
load. These results indicate that TO and TE are transported into lymph
similarly, and that cholesterol absorption and transport are similar
irrespective of whether TO or TE is the TG source. The data suggest that
trans fatty acid-induced hypercholesterolemia is not due to altered
intestinal absorption and transport of cholesterol.
