This study was designed to compare the effects of three prolonged exercises on plasma
myeloperoxidase concentrations, used as marker of neutrophil degranulation. Seven
healthy subjects underwent three effort trials (45 % VO2max during 4 h, 60 % VO2max during 3 h, 75 % VO2max during 2 h) at one-month intervals. Blood samples were collected before, during
and after exercise. Myeloperoxidase levels were measured by radioimmunoassay. We observed
a significant increase in myeloperoxidase concentration (+ 85 %) at the end of our
three prolonged exercises (p < 0.05). This myeloperoxidase increase was not correlated
with the modification of neutrophil count, suggesting that neutrophil degranulation
is independent of their mobilisation.
Key words
Exercise duration - exercise intensity - myeloperoxidase