Contribution of net hepatic glycogenolysis to glucose production
during the early postprandial period.
Petersen, Kitt F., Thomas Price, Gary W. Cline, Douglas L. Rothman,
and Gerald I. Shulman.
Department of Internal Medicine, Yale University School of
Medicine,
APStracts 2:0218E, 1995.
Relative contributions of net hepatic glycogenolysis and
gluconeogenesis to glucose production during the first 12 hours of a
fast were studied in 13 healthy volunteers by non-invasively
measuring hepatic glycogen content using 13C nuclear magnetic
resonance spectroscopy. Rates of net hepatic glycogenolysis were
calculated by multiplying the change in liver glycogen content with
liver volume determined by magnetic resonance imaging. Rates of
gluconeogenesis were calculated as the difference between rates of
glucose production determined with an infusion of [6,6-2H]glucose and
net hepatic glycogenolysis. At 6 pm a liquid mixed meal (1000 Kcal;
60% as glucose) was given to which [2-2H]glucose was added to trace
glucose absorption. Hepatic glycogen content was measured between:
11pm-1am and 3am-6am. At 11 pm the concentration was 470 mM and
decreased linearly during the night. The mean liver volume was
1.47+/-0.06 liter. Net hepatic glycogenolysis [5.8+/-0.8 [mu]mol/(kg
body wt-min)] accounted for on average 45+/-6% and gluconeogenesis
for 55+/-6% of the rate of whole body glucose production [12.6+/-0.6
[mu]mol/(kg body wt-min)]. In conclusion, this study shows that even
early in the phase of the postabsorptive period when liver glycogen
stores are maximal, gluconeogenesis contributes 50% to hepatic
glucose production.
Received 25 September 1995; accepted in final form 10 October
1995.
APS Manuscript Number E470-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95