Estrogen administration, postexercise tissue oxidative stress and vitamin C status in male rats.
Estrogen can putatively act as an antioxidant and protect tissues from exercise-induced oxidative stress. To test the in vivo efficacy of estrogen, the effects of 2 weeks of daily estrogen (40 microg x kg(-1) body weight beta-estradiol 3-benzoate) injection on indices of immediate postexercise oxidative stress and antioxidant status were determined in adult male rats, with and without 8 weeks of prior dietary vitamin E deprivation. The treadmill running protocol (60 min at 21 m x min(-1), 12% grade) induced significant oxidative stress as indicated by muscle glutathione status. Estrogen administration had little effect on postexercise tissue glutathione status, superoxide dismutase and glutathione peroxidase activity, and vitamin E levels. Estrogen administration induced significant reductions in muscle, liver, and heart vitamin C concentrations following exercise, as well as in unexercised male rats. Tissue vitamin C loss was not directly mediated through liver glycogen or glutathione status. Thus, estrogen administration generally did not appear to influence postexercise tissue indices of oxidative stress or antioxidant status and may have contributed to a decline in overall antioxidant protection by inducing losses in tissue vitamin C content.
Tiidus
P M
PM
Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, ON, Canada. ptiidus@mach1.wlu.ca
Bombardier
E
E
Hidiroglou
N
N
Madere
R
R
D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism*; D001835:Body Weight / Q000187:drug effects; D004967:Estrogens / Q000494:pharmacology*; D005978:Glutathione / Q000187:drug effects / Q000378:metabolism; D019803:Glutathione Disulfide / Q000187:drug effects / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000187:drug effects / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D006321:Heart / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000187:drug effects / Q000378:metabolism; D014810:Vitamin E / Q000378:metabolism
D004967:Estrogens; D014810:Vitamin E; D006003:Glycogen; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione; D001205:Ascorbic Acid; D019803:Glutathione Disulfide