Abstract
Thirty-nine adult male guinea pigs, assigned to castratedsedentary, normal-sedentary,
castrated-replacement-sedentary, castrated-trained, normal trained and castrated-replacement-trained
treatment groups, were employed to assess the role of testosterone in exercise-induced
glycogen supercompensation in skeletal muscle. Beginning on the seventh post-operative
day, trained animals were run every other day for a total of ten trials, with trials
one through five and trials six through ten being 30 and 40 min in duration, respectively.
Forty-eight hours after the final exercise trial and 27 days after the onset of the
experiment, the guinea pigs were killed and the vastus lateralis was rapidly removed
for glycogen analysis. Normal-trained and castrated-replacement-trained treatment
group glycogen means were significantly greater than those of castrated-trained and
all sedentary treatment groups. The castrated-trained glycogen mean, which did not
statistically differ from those of castrated-replacement-sedentary and normal-sedentary
groups, was significantly greater than the glycogen mean of its sedentary counterpart.
It was concluded that muscle glycogen levels are dependent on the chronic activity
of the animal and this dependence is mediated in part through testosterone.
Key words
Exercise - Glycogen - Testosterone - Castration - Skeletal Muscle
1 This work was partially supported by the UCLA Academic Senate Committee on Research
and by the Easter Seal Research Foundation of the National Easter Seal Society for
Crippled Children
and Adults, Inc.
