Journal of Applied Physiology, Vol 47, Issue 2 273-278, Copyright © 1979 by American Physiological Society
Effect of somatostatin on plasma glucagon and insulin, and glucose turnover in exercising sheep
R. P. Brockman
To examine the roles of glucagon and insulin in exercise, four sheep were
run on a treadmill with and without simultaneous infusion of somatostatin
(SRIF), a peptide that suppresses glucagon and insulin secretion. SRIF
infusion suppressed the exercise-induced rise in plasma glucagon during
both moderate (5--5.5 km/h) and strenuous exercise (7.0 km/h). In addition,
SRIF prevented the rise insulin concentrations during moderate exercise.
During strenuous exercise, insulin concentrations were depressed in both
groups. The infusion of SRIF was associated with a reduction in
exercise-induced glucose production, as determined by infusion of
[6-3H]glucose, during the first 15 min of both moderate and strenuous
exercise compared to controls. Beyond 15 min glucose production was not
significantly altered by SRIF infusions. These data are consistent with
glucagon having an immediate, but only transient, stimulatory effect on the
exercise-induced hepatic glucose production.
