Journal of Applied Physiology, Vol 38, Issue 6 961-964, Copyright © 1975 by American Physiological Society
Glycogen replenishment following exercise: effects of denervation and tenotomy
R. A. Ratliff and D. R. Lamb
To examine the role of the nervous system in the rapid replenishment of
muscle glycogen that occurs after exhaustive exercise, glycogen stores and
glycogen synthetase activity of normal gastrocnemius muscles of untrained
and trained guinea pigs were compared to glycogen and synthetase activity
of trained gastrocnemius muscles that were denervated or tenotomized
immediately after exhaustive exercise and then allowed to recover for 48 h.
The trained tenotomized muscles, but not the denervated muscles, had
significantly (P smaller than 0.05) less glycogen than the trained normal
muscles. These results suggest that neither nerve impulse conduction nor
tropic substances contained in neural tissue proximal to the site of
denervation mediate glycogen replenishment after exercise. The active,
glucose 6-phosphate independent (I) form of glycogen synthetase activity
was reduced by both denervation and tenotomy at 48 h after exercise with no
significant (P greater than 0.05) differences detected for the total of I
and D (glucose 6-phosphate dependent) synthetase activity. Synthetase I
relative to total synthetase activity was similar in trained and untrained
normal muscles, both of which had significantly (P smaller than 0.05)
greater relative I activities than denervated or tenotomized muscles. These
synthetase data show that elevated glycogen stores following recovery from
exercise may be observed in the absence of increased levels of glycogen
synthetase activity.
