Use of measurements of ethanol absorption from the stomach and
intestine to assess human ethanol metabolism.
Levitt, Michael D., Ricardo Li, Eugene G. Demaster, Michael Elson,
Juliefurne, and David G. Levitt, M. D., Ph. D.
Research Service, Mpls. Veterans Affairs Medical Center (M.D.L.,
R.L., E.G.D., M.E., J.F.) and the Dept. of Physiology, University of
Minnnesota (D.G.L.)
APStracts 4:0185G, 1997.
Controversy exists concerning the site (stomach versus liver) and
magnitude of first-pass metabolism of ethanol. We qauntitated gastric
and total ethanol absorption rates in five male subjects and utilized
these measurements to evaluate first-pass metabolism. Gastric
emptying of ethanol (0.15 g/kg) was determined via a gamma camera and
gastric absorption from the ratio of gastric ethanol:14C-PEG. Gastric
absorption accounted for 30% and 10% of ethanol administered with
food and water, respectively. With food, estimated gastric mucosal
ethanol concentrations fell from 19 mM to 5 mM over 2 hours.
Calculations using these concentrations and kinetic data for gastric
ADH showed <2% of the dose underwent gastric metabolism.
Application of observed ethanol absorption rates to a model of human
hepatic ethanol metabolism indicated that only 30% and 4% of the dose
underwent first-pass metabolism when administered with food and
water, respectively. We conclude that virtually all first-pass
ethanol metabolism occurs in the liver and first-pass metabolism
accounts for only a small fraction of total clearance.
Received 7 May 1997; accepted in final form 10 July 1997.
APS Manuscript Number G165-7.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 24 July 1997