Journal of Applied Physiology, Vol 69, Issue 6 2197-2201, Copyright © 1990 by American Physiological Society
Effects of selective hepatic vagotomy on running endurance in rats
B. Doiron, S. Cardin, G. R. Brisson and J. M. Lavoie
Department d'Education Physique, Universite de Montreal, Quebec, Canada.
The liver, through the afferent ways of the vagus hepatic nerve, may
influence metabolic adaptations during exercise. This study assesses the
functional significance of this hepatic innervation by determining the
effect of a selective hepatic vagotomy (HV) on running endurance time
during submaximal activity in rats subjected to an overnight 50% food
restriction. The time to exhaustion was similar for the groups of HV and
sham-operated (SHM) rats [66 +/- 15 vs. 64 +/- 21 (SD) min]. The HV group
was associated with higher resting levels (P less than 0.05) of hepatic
glycogen and plasma glucose. No significant differences were observed
between HV and SHM rats at rest and after exercise for muscle glycogen,
free fatty acids, insulin, glucagon, and lactate concentrations. These data
indicate that if hepatic glucoreceptors do exist and contribute to the
metabolic regulation of exercise, their functional significance is
secondary to more important regulatory mechanisms.
