Glycerol production and utilization in humans: sites and
quantitation.
Landau, Bernard R., John Wahren, Stephen F. Previs, Karin Ekberg,
Visvanathan Chandramouli, and Henri Brunengraber.
Departments of Medicine, Biochemistry and Nutrition, Case Western
Reserve University, School of Medicine, Cleveland, Ohio 44106 and
Department of Clinical Physiology, Karolinska Hospitals S-171 76
Stockholm, Sweden
APStracts 3:0151E, 1996.
Liver is assumed the major site of glycerol uptake and fatty acid
reesterification. [U-13C]Glycerol was infused into ten 60 h-fasted
healthy subjects. Measured were: (i) blood glycerol concentrations
and 13C-enrichments in brachial and pulmonary arteries, and hepatic,
renal, superficial and deep forearm veins, (ii) glycerol appearance
rates in systemic circulation, (iii) splanchnic bed and kidney
glycerol uptakes using balance and tracer methodology. Glycerol
concentrations were one-fifth in hepatic, one-half in renal, 40% more
in superficial and the same in deep vein and pulmonary artery as in
brachial artery blood. Glycerol enrichments were one-fifth in
hepatic, two-thirds to three-quarters in renal and superficial veins
and the same in pulmonary as in brachial artery blood. Splanchnic
glycerol uptake was 29% and kidney glycerol uptake was 17% of
glycerol's rate of appearance, 5.11 [mu]mol x min 1 x kg 1.
Splanchnic fatty acid uptake was 25% of calculated fatty acid
release. Glycerol contributed 15% to glucose production. Most 13C
-glycerol uptake by splanchnic bed and kidneys was incorporated into
glucose. Thus, in 60 h-fasted individuals, most glycerol uptake does
not occur in liver and the generally accepted role of the liver in
fatty acid reesterification is in doubt.
Received 2 April 1996; accepted in final form 24 July 1996.
APS Manuscript Number E165-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 21 August 1996