The single cell gel electrophoresis (SCG) assay was used to compare the occurrence
of DNA damage in peripheral white blood cells in 6 trained (TR) and 5 untrained (UT)
men after exhaustive exercise. The subjects completed an incremental treadmill test
until exhaustion (maximal lactate: 12.9 ± 1.7 in TR and 12.2 ± 2.5 mmol · l-1 in UT). A clear and significant increase of DNA migration from 2.31 ± 0.20 (TR) and
2.22 ± 0.16 (UT) at rest to 2.65 ± 0.30 (TR) and 3.00 ± 0.41 tail moment (UT) was
found 24 hours after exercise. Noteworthy is that the increase of DNA migration was
significantly lower in TR (+ 18.7 ± 6.8 %) compared to UT (+ 35.7 ± 8.9 %). Plasma
levels of malondialdehyde (MDA) were not significantly increased in TR and UT after
exercise. At rest and 15 minutes after exercise MDA-values were significantly lower
in TR compared to UT. In conclusion the present investigation demonstrates the occurrence
of DNA damage in white blood cells following exhaustive exercise. This observation
may be induced by oxidative stress. Our data suggest that adaption to training seems
to be capable of reducing free radical associated effects, such as DNA damage. Further
investigations are needed to clarify the causal mechanisms and biological relevance
of exercise-induced DNA damage.
DNA damage - single cell gel test - leucocytes - oxidative stress - lipid peroxidation
- exercise - training adaption