Effects of acute exercise on the gluconeogenic capacity of periportal and perivenous
hepatocytes.
Désy, François, Yan Burelle, Patrice Bélanger, Marielle Gascon-Barré, and Jean-Marc
Lavoie.
1Département de Kinésiologie and 2Département de Pharmacologie, Université de
Montréal, Montréal, Québec H3C 3J7, Canada
APStracts 8:0294A, 2001.
The present study was conducted to examine the effect of a single bout of exercise
(rodent treadmill, 60 min at 26 m/min, 0% grade) on the gluconeogenic activity of
periportal hepatocytes (PP-H) and perivenous hepatocytes (PV-H) in fasted (18 h) rats.
Isolated PP-H and PV-H, obtained by selective destruction following liver perfusion with
digitonin and collagenase, were incubated with saturating concentrations of alanine
(ALA; 20 mM) or a mixture of lactate + pyruvate (LAC+PYR; 20:2 mM) to determine
the glucose production flux (Jglucose) in the incubation medium. Results show that, in
the resting conditions, Jglucose from all exogenous substrates was significantly higher (P
< 0.01) in PP-H than PV-H. Exercise, compared with rest, resulted in a higher Jglucose
(P < 0.01) from LAC+PYR substrate in the PV-H but not in the PP-H, resulting in the
disappearance of the difference in Jglucose between PP-H and PV-H. Exercise, compared
with rest, led to a higher Jglucose (P < 0.01) from ALA substrate in both PP-H and PV-
H. However, the exercise-induced increase in Jglucose (gluconeogenic activity) from
ALA substrate was higher in PV-H than in PP-H, resulting, as from LAC+PYR substrate,
in the disappearance (P > 0.05) of the difference of Jglucose between PP-H and PV-H.
It is concluded that exercise differentially stimulates the gluconeogenic activity of PV-H
to a larger extent than PP-H, indicative of a heterogenous metabolic response of
hepatocytes to exercise.
Received 28 November 2000; accepted in final form 9 May 2001
APS Manuscript Number A1132-0.
Article publication pending J Appl Physiol
ISSN 1080-4757 Copyright 2001 The American Physiological Society.
Published in APStracts on 18 June 2001