The effects of moderate, strenuous, and overtraining on oxidative stress markers and DNA repair in rat liver.
Physical exercise above a certain load has been suggested as being a cause of oxidative stress. We have tested whether training with moderate (MT), strenuous (ST), or over (OT) load can cause alterations in the activities of antioxidant enzymes, lipid peroxidation, protein oxidation, DNA damage, or activity of 8-oxoG-DNA glycosylase (OGG1) in rat liver. The levels of corticosterone decreased in all exercising groups but the differences were not significant. Adrenocorticotrophin hormone (ACTH) levels decreased, not significantly, in MT and OT compared to C. Activity levels of antioxidant enzymes did not change significantly in the liver. The levels of reactive carbonyl derivative (RCD) content decreased in the liver of exercising animals, and the differences reached significance between control and moderately trained groups. The changes in the levels of lipid peroxidation (LIPOX) were not significant, but were lower in the exercised groups. The 8-hydroxydeoxyguanosine (8-OHdG) levels increased in the OT group, and the activity of OGG1 measured from crude cell extracts tended to increase in MT and ST. The findings of this study imply that overtraining induces oxidative damage to nuclear DNA, but not to liver lipids and proteins.
Ogonovszky
Helga
H
Institute of Sport Science, Faculty of Physical Education and Sport Science, Semmelweis Univ., 1123 Budapest, Alkotas u. 44, Hungary.
Sasvári
Maria
M
Dosek
Agoston
A
Berkes
István
I
Kaneko
Takao
T
Tahara
Shoichi
S
Nakamoto
Hideko
H
Goto
Sataro
S
Radák
Zsolt
Z
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D004249:DNA Damage; D004260:DNA Repair; D015227:Lipid Peroxidation; D008099:Liver / Q000737:chemistry; D018384:Oxidative Stress / Q000502:physiology*; D010805:Physical Conditioning, Animal; D051381:Rats; D017208:Rats, Wistar
D000324:Adrenocorticotropic Hormone