Exercise induced chromosomal damage was evaluated in trained and untrained subjects,
who performed treadmill running at 85 % of maximal oxygen uptake for 30 min. The subjects
had their peripheral blood taken before, immediately after and 30 min after the running
test for the analysis of lymphocyte chromosomal damage that was evaluated by micronucleus
assay. The blood samples were also subjected to X-ray irraddiation in vitro to examine
the modification of exercise induced chromosomal damage by a secondarily induced oxidative
stress. Spontaneous chromosomal damage in lymphocytes did not significantly increase
at least until 30 min after the running both in the trained and untrained subjects.
However, the X-ray-induced chromosomal damage was significantly enhanced at 30 min
after the running in the untrained group, but not in the trained group. The ratio
of X-ray-induced/spontaneous chromosomal damage also tended to increase after the
running only in the untrained group. These preliminary results suggest that intensive
exercise induced very slight chromosomal damage only in the untrained group, which
could be intensified by the secondarily induced oxidative stress.
Key words
Exercise - chromosomal damage - lymphocytes - antioxidants - radiation
