title: Effect of repeated exercise on urinary 8-hydroxy-deoxyguanosine excretion in humans.
abstract: The purpose of this study was to investigate the effect of repeated exercise on oxidative damage to DNA in 10 well trained long distance runners who participated in an 8-day training camp. The average running distance during the camp was 30 +/- 3 km/day. The amount of urinary 8-hydroxy-deoxyguanosine (8-OHdG) excretion was used to estimate the oxidative DNA damage. Urine samples were collected for both a 3-day control period as well as throughout the camp. Blood samples were drawn after overnight fasting both before and after the camp. Urinary 8-OHdG excretion was significantly increased during the camp compared to the control period (265.7 +/- 75.5 vs. 335.6 +/- 107.4 pmol/kg/day, P < 0.05). The content of 8-OHdG in the lymphocyte DNA on the day after finishing the camp did not differ from that before the camp. Plasma TBARS, LDH, CK, CK-MB, and myoglobin significantly rose after the camp (P < 0.05). The plasma beta-carotene levels tended to rise after the camp, while the plasma alpha-tocopherol levels increased significantly after the camp (P < 0.05). These results indicate that repeated exercise augments oxidative stress and the DNA is also injured by exercise-induced reactive oxygen species. However, the oxidative damage to DNA is not accumulated by consecutive exercise, although it is sustained as long as the exercise is repeated.
authors.affiliation: Saga Research Institute, Otsuka Pharmaceutical Co., Ltd., Saga, Japan. k_okamura@research.otsuka.co.jp
authors.forename: K
authors.initials: K
authors.lastname: Okamura
authors.forename: T
authors.initials: T
authors.lastname: Doi
authors.forename: K
authors.initials: K
authors.lastname: Hamada
authors.forename: M
authors.initials: M
authors.lastname: Sakurai
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshioka
authors.forename: R
authors.initials: R
authors.lastname: Mitsuzono
authors.forename: T
authors.initials: T
authors.lastname: Migita
authors.forename: S
authors.initials: S
authors.lastname: Sumida
authors.forename: Y
authors.initials: Y
authors.lastname: Sugawa-Katayama
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D003404:Creatinine / Q000652:urine; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000652:urine; D006801:Humans; D008297:Male; D009211:Myoglobin / Q000097:blood; D010084:Oxidation-Reduction; D010807:Physical Endurance; D005082:Physical Exertion; D012420:Running; D014810:Vitamin E / Q000652:urine; D019207:beta Carotene / Q000652:urine
chemical_list: D009211:Myoglobin; D019207:beta Carotene; D014810:Vitamin E; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003404:Creatinine; D003849:Deoxyguanosine