Increased net hepatic glucose output from gluconeogenic precursors
following high-sucrose diet feeding in male rats.
Pagliassotti, Michael J., and Piper A. Prach.
Section of Pediatric Nutrition and Center for Human Nutrition,
University of Colorado Health Sciences Center, Denver, CO., 80262
APStracts 3:0303R, 1996.
A high sucrose diet reduces the ability of insulin to suppress hepatic
glucose production (hepatic insulin resistance) in rats. The purpose
of the present study was to investigate the contribution of hepatic
gluconeogenesis to sucrose-induced hepatic insulin resistance.
Single-pass liver perfusions were performed on 24 h food- deprived
male Wistar rats following 8 wk on either a high corn starch (ST, 68%
of energy) or high sucrose (SU, 68% of energy) diet. Hepatic glucose
output (HGO, [mu]mol of glucose/ min per gram) in the presence of
lactate, alanine or dihydroxyacetone (DHA) was used as an estimate of
gluconeogenic capacity, since liver glycogen levels after the 24 h
fast were negligible (<1.2 mg/g). HGO was significantly
(p<0.05) greater in SU vs. ST at all concentrations of lactate,
alanine, and DHA. Maximal rates of HGO were 1.9+/-0.4 and 2.8+/-0.3
at 10 mM lactate, 0.6+/-0.2 and 1.4+/-0.3 at 10 mM alanine, and
1.7+/-0.3 and 2.6+/-0.2 at 20 mM DHA in ST and SU, respectively. When
HGO was matched between SU and ST by using different precursor
concentrations, there was a significant (p<0.05) reduction in
the ability of insulin (175 [mu]U/ml) to suppress HGO in SU vs. ST.
These data suggest that sucrose feeding increases gluconeogenesis
from lactate, alanine and DHA, and that this route of glucose
production is resistant to insulin suppression.
Received 20 May 1996; accepted in final form 30 July 1996.
APS Manuscript Number R280-6.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 29 August 1996