Oestrogen attenuates post-exercise myeloperoxidase activity in skeletal muscle of male rats.
The effects of 2 weeks of oestrogen (40 microg kg BW-1 beta-estradiol 3-benzoate) injection on 24 h post-exercise myeloperoxidase (MPO) activities were determined in plantaris and soleus muscles and liver of sexually mature male and female rats. The treadmill running protocol (45-60 min, at 28 m min-1, 15% grade) induced significant elevations in muscle MPO activities 24 h post-exercise in male rats, while prior oestrogen administration to male rats eliminated the post-exercise elevations in muscle MPO activities. Female rats experienced no significant post-exercise elevations in muscle MPO activities. Hence oestrogen administration to male rats attenuated post-exercise muscle MPO activities to levels found in female animals. Liver MPO activities were not significantly affected by exercise, gender or oestrogen administration. Oestrogen may be a factor in diminishing 24 h post-exercise skeletal muscle leukocyte infiltration and inflammatory response in both male and female muscle.
Tiidus
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PM
Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, Ont., Canada.
Bombardier
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D000818:Animals; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000201:enzymology; D009504:Neutrophils / Q000473:pathology; D009195:Peroxidase / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
C074283:estradiol 3-benzoate; D004958:Estradiol; D009195:Peroxidase