Blood mononuclear cells mobilization and cytokines secretion during prolonged exercises

This study was designed to compare the effects of three prolonged exercises varying in their intensity and duration, on blood mononuclear cell mobilization and cytokine secretion (IL(1)-IL(2)), Seven healthy subjects underwent three effort trials (45% VO(2)max during 4 h - 60% VO(2)max during 3 h - 75% VO(2)max during 2 h) at one-month intervals. Blood samples were drawn before, different times during exercise and also after exercise. Prolonged exercises induced a transient increase in blood mononuclear cells which occurred across all intensity levels. We also observed a significant increase in plasma IL(1) level during exercise which correlates with the exercise intensity. The mean IL(1) level increased up to 2.5 times after the three proposed exercises (p < 0.05). Plasma IL(2) level decreased at the end of prolonged exercises irrespective of the exercise intensity. No correlation was observed between blood mononuclear count and cytokine determination. Our data suggest that blood mononuclear cells mobilization is associated but not correlated with alterations of cytokine levels.