effect of eight weeks of resistance training on pax7 and myod in fast and slow-twitch skeletal muscles of old rats

Background: box 7 protein (pax7) and myogenic differentiation (myod) proteins are the essential proteins to regulate the satellite cell and muscle hypertrophy.objectives: we aimed to investigate the effect of resistance training (rt) on pax7 and myod in soleus and extensor digitorum longus (edl) muscles of old rats.methods: in this experimental study, 12 old female rats were randomly divided into two groups including rt and control groups. the rt program was three days a week for eight weeks, in which the rats climbed a one-meter vertical ladder with 26 steps. the carried weights varied from 50% of body weight in the first week to 100% of body weight in the 8th week. kolmogorov- smirnov test and independent sample t test was used for statistical analysis (p≤0.05).results: myod protein in rt group significantly increased in soleus and edl muscles compared with the control group (p = 0.001). also, pax7 significantly increased in the soleus muscle in the rt group compared with control group (p = 0.002); nevertheless, there was no significant difference in pax7 protein in the edl muscle between the rt and control groups (p = 0.10).conclusion: rt can lead to proliferation and renewal of satellite cells in the soleus and edl muscles by increasing pax7 and myod proteins.