Skeletal muscle fibre number in the rat from youth to adulthood
The purpose of this study was to determine whether or not there was a decrease in skeletal muscle fibre number in the rat from the early postnatal period to adulthood. Twelve male Sprague-Dawley rats were used in the study. At 25 days of age the animals underwent surgical removal of the soleus and tibialis anterior muscles from one hindlimb. At 180 days of age, 6 of the animals were killed and the soleus and tibialis anterior muscles from the contralateral leg were removed. The same procedure was carried out on the remaining 6 animals at 365 days of age. Fibre number was determined by the nitric acid digestion method for the soleus muscles and the mean fibre dry weight method for the tibialis anterior muscles. There was no difference in fibre number for either muscle between 25 days of age and 180 days of age or between 25 days of age and 365 days of age. The results of this study indicate that there is no change in skeletal muscle fibre number from the early postnatal period until adulthood in the rat.
Timson, B. F., and G. A. Dudenhoeffer. "Skeletal muscle fibre number in the rat from youth to adulthood." Journal of anatomy 173 (1990): 33-36.
Journal of Anatomy