The satellite cells of normal anuran skeletal muscle

Population counts and size measurements of satellite cell nuclei and myonuclei were carried out on the normal gastrocnemius muscles of adult Rana pipiens and Rana clamitans. Satellite cell profiles occurred with an observed frequency of about 1.3% in the muscles of the R. pipiens, and with an observed frequency of about 1.6% in the muscles of the R. clamitans. These frequencies were not found to be significantly different. The observed frequencies were corrected for the sampling bias introduced by the difference in the mean size of the satellite cell nuclei and myonuclei. This correction suggests that R. pipiens and R. clamitans both have a true satellite cell frequency of approx 2.7%. Analysis of these data indicates that the satellite cells of the normal anuran gastrocnemius occur in sufficient numbers to account for the regeneration seen after injury to this muscle.