Glucose production in glycogen storage disease i is not associated
with increased cycling through hepatic glycogen.
Rother, Kristina I., and W. Frederick Schwenk.
Department of Pediatrics, Mayo Clinic, Rochester, Minnesota
APStracts 2:0111E, 1995.
Children with glycogen storage disease type I (GSDI) lack the ability
to convert glucose-6-P to glucose, and yet are able to produce
glucose endogenously. To test the hypothesis that the source of this
glucose is from increased cycling of glucose moieties through hepatic
glycogen, six children with GSDI were studied on two occasions,
receiving enteral glucose for 6-h at 35 or 50 _mol_kg-1_min-1, along
with [6,6-2H2]glucose to measure plasma glucose flux and [1
-13C]galactose to label intrahepatic UDP-glucose. After 3-h,
acetaminophen was given to estimate UDP-glucose flux (reflecting the
rate of glycogen synthesis). Mean steady state plasma glucose
concentrations (4.8+/-0.2 vs. 5.8+/-0.1 mM) and total flux (34.8+/
-1.7 vs. 47.5+/-2.0 _mol_kg-1_min-1) were increased (p<0.05 or
better) on the high infusion day. Endogenous glucose production was
only detectable on the low infusion day (2.0+/-0.5 _mol_kg-1_min-1).
UDP-glucose flux was increased (p<0.05) on the high infusion day
(25.8+/-1.6 vs. 34.7+/-4.1), ruling out cycling of glucose moieties
through glycogen with release of glucose by debrancher enzyme as the
source of glucose production.
Received 19 October 1994; accepted in final form 10 May 1995.
APS Manuscript Number E432-4.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 26 May 1995.