The role of the intestine in chylomicron remnant clearance.
Mansbach, Charles M., Ii, and Regenia F. Dowell.
Department of Medicine, Division of Gastroenterology, The
University of Tennessee, Memphis, Memphis, TN 38163 and The Veterans
Administration Medical Center, Memphis, TN 38104
APStracts 2:0049G, 1995.
When 810 [mu]mol of glyceryltri 3H-oleate are infused intraduodenally
over 6 hours into rats, 29 % of the triacylglycerol-acyl groups in
the mucosa are not from the infusate. We tested the hypothesis that
chylomicron remnants contribute to the mucosal pool of non-dietary
triacylglycerol- acyl groups since the acyl group composition of the
chylomicron remnants was 58 % oleate as compared to their parent
chylomicrons' 90 %. Purified 3H-remnants were generated from
chylomicrons formed in rats receiving glyceryl-tri 3H-oleate
intraduodenally with 95 % of the remnant dpm being in
triacylglycerol. The 3H-remnants were infused intravenously into rats
receiving either saline or 135 [mu]mol/h glyceryltrioleate
intraduodenally. In the saline infused rats, 32 % of the infused 3H
-dpm were in the proximal and 19 % in the distal intestine. 32 % were
in the liver. In the fat infused rats, 12 % of the infused 3H-dpm
were in the proximal and 5 % in the distal gut. 29 % were in the
liver. When 3H-cholesterol labeled remnants were infused
intravenously and saline intraduodenally, the percentage uptake into
the mucosa was nearly the same as with the triacylglycerol label but
the comparable uptake by the liver increased. We conclude that the
intestine competes with the liver for chylomicron remnant
triacylglycerol and cholesterol.
Received 20 December 1993; accepted in final form 8 March 1995.
APS Manuscript Number G508-3.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 28 March 1995.