AJP - Regulatory, Integrative and Comparative Physiology, Vol 268, Issue 1 72-R77, Copyright © 1995 by American Physiological Society
Effect of liver denervation on glucose production during running in guinea pigs
M. M. Wiersma, J. Vissing, K. J. Mikines, A. B. Steffens and H. Galbo
Department of Medical Physiology, Panum Institute, Copenhagen, The Netherlands.
Activity in sympathetic liver nerves has been proposed to be important for
glucose production in exercising humans. However, liver denervation does
not influence the exercise-induced increase in glucose production in the
rat and dog. These species have a poor sympathetic liver innervation in
contrast to the rich innervation in humans. The effect of liver denervation
on glucose production during exercise was therefore studied in the guinea
pig, a species with a rich sympathetic hepatic innervation comparable to
that of humans. Guinea pigs were selectively liver denervated (n = 9) or
sham operated (n = 8) and instrumented with a carotid and a jugular
catheter. One week later they ran on a treadmill at 32 m/min for 20 min.
Glucose turnover was evaluated by a primed constant-rate intravenous
infusion of [3-3H]glucose. Arterial blood was sampled for analysis of
hormones and metabolites. At rest, liver-denervated guinea pigs had lower
glucose turnover and plasma concentrations of glucose, glycerol, and
cortisol than control animals. During running, the increase in hepatic
glucose production was similar in the two groups (4.1 +/- 0.8 vs. 3.8 +/-
0.7 mumol.min-1.100 g-1 in control animals) and so were hepatic (247 +/- 25
vs. 246 +/- 45 mmol glucose units/kg wet wt in control animals) and muscle
glycogen concentrations at the end of exercise.(ABSTRACT TRUNCATED AT 250
WORDS)
