The effect of 8 weeks exercise activity and estrogen supplementation on proliferation satellite cell in rats

Introduction: Animal and human studies indicated that overtension and stress, releasing the inflammation
substance and growth factor being produced following exercise lead to satellite cell activation and proliferation.
The aim of the present study was to investigate the effect of eight weeks of exercise activity and estrogen
supplementation on the proliferation of satellite cells in rats. Methods: Thirty-eight rats were selected and
randomly divided into 4 groups as follows: 1- exercise activity (E), 2- Estrogen supplementation (ES), 3-
exercise activity + Estrogen supplementation (EE), 4- control. Then, E and EE groups performed endurance
exercise for 8 weeks, 3 sessions in each. In each week, ES and EE groups were implanted subcutaneously with
0.6 of Estrogen supplement. Soleus muscle was retracted and placed into 10% of Formalin. In a pathological
lab, satellite cell numbers were counted and recorded using a light microscope through Hemotoxin Eosin
staining and Immunohistochemistry for CD 56. Results: The results of one-way ANOVA indicated that the
proliferation of satellite cells were differents on study groups. Exercise activity causes a 16% increase in
satellite cell number in rats, while a 71% decrease in satellite cell number was observed in long-term exercise
activity plus estrogen supplementation group. Besides the research result indicated a 5 time –increase in
satellite cells in group received estrogen supplementation for long term. Conclusion: estrogen may act in
inflammation responses and skeletal muscle injuries as a consequence of unaccustomed exercise or other
detrimental effects. Moreover, this research confirmed that estrogen supplementation effects on satellite cell
proliferation in rats that it would appear that many different factors play a role in increase and proliferation of
these cells, so it has been influenced by estrogen levels.