Journal of Applied Physiology, Vol 46, Issue 4 654-657, Copyright © 1979 by American Physiological Society
Effect of work-induced hypertrophy on skeletal muscle of tumor- and nontumor-bearing rats
J. A. Norton, S. F. Lowry and M. F. Brennan
Synergistic muscles (soleus and plantaris) from a gastrocnemius-tenotomized
hindlimb were compared to the same muscles in a sham-operated hindlimb in
both tumor-bearing and non tumor-bearing rats. In nontumor-bearing animals
muscle from the tenotomized hindlimb had a significant increase in wet
weight (26%), percent-water (5%), and total nitrogen/muscle (10%)
consistent with muscular hypertrophy. In tumor-bearing animals, muscle from
the tenotomized hindlimb had a significant increase in wet weight and
percent water, but there was no significant difference in total
nitrogen/muscle. As the tumor burden increased, the final muscle weight, in
both the tenotomized and sham-operated hindlimb, was found to decrease
proportionately. Only in animals with large (23% body wt) tumor burdens did
hypertrophied muscle weigh significantly less than sham-operated muscle
from nontumor-bearing animals. This indicated that, in rats with large
tumor burdens, work-induced hypertrophy was unable to preserve muscle mass
despite the fact that hypertrophied muscle was 24% heavier than
contralateral sham-operated muscle.
