Oestrogen influence on myogenic satellite cells following downhill running in male rats: a preliminary study

Aim: This study examined the effect of oestrogen supplementation in rats on myogenic satellite cell quantities in type I and II muscles following eccentric exercise. Methods: Gonad intact adult male rats divided into four groups, oestrogen supplemented (25 mg oestrogen pellet) control (EC), oestrogen supplemented, exercised (EE), sham (no oestrogen) control (SC) and sham, exercised (SE). After 1 week of oestrogen exposure the EE and SE animals performed 90 min of intermittent downhill running (5 min running/2 min rest @−13.5° incline and 17 m min−1 speed). Seventy‐two hours later exercised (EE and SE) and control (EC and SC) animals were killed and blood samples taken and soleus and white (superficial) vastus muscles surgically removed. Histochemical sections of soleus and white vastus muscles were examined for myogenic satellite cell content by use of Pax7 antibody and for neutrophil content by use of haematoxylin and eosin (H and E) staining procedures. Results: Downhill running resulted in significant elevations in satellite cells and neutrophils detected in both soleus and white vastus muscle samples (P