Immunoregulatory Hormones, Circulating Leucocyte and Lymphocyte Subpopulations before and after Endurance Exercise of Different Intensities*

Abstract

Sixteen subjects (male, age: 26.3±3.5 years, weight: 75.1±6.5 kg, maximal oxygen uptake: 53.6±6.7 ml·min^-1·kg^-1) performed endurance exercises at 100% (exhaustive), and 85% (limited) of the individual anaerobic threshold [IAT; workload (100% IAT): 3.00±0.50 W·kg^-1, duration of both exercises: 87±21 min]. Before (b), immediately (0 p), 60 min (60 p), 120 min (120 p) and 24 hours (24 hp) after exercise, leucocyte subpopulations (flow cytometry) as well as epinephrine, norepinephrine, cortisol, β-endorphin and ACTH were determined.

At 0 p, 60 p and 120 p, granulocytes were significantly higher at 100% IAT than at 85% IAT, lymphocytes and monocytes did not differ. At 60 p and 120 p, granulocytes had highest, lymphocytes lowest values. CD8⁺ -and CD 16⁺ -lymphocytes showed greater changes than CD3⁺-, CD4⁺-, CD19⁺-lymphocytes and were significantly higher at 100% IAT than at 85% IAT (0 p). Epinephrine and norepinephrine were significantly higher at 100% IAT than at 85% IAT. cortisol, ACTH and β-endorphin increased at 100% IAT, but not at 85% IAT (0 p). Significant correlations were calculated for cortisol (0 p) versus granulocytes (60 p, 120 p) at 100% IAT. Epinephrine did not correlate to increases of lymphocytes or lymphocyte subpopulations.

In conclusion, increases of granulocytes, CD16⁺ -and CD8⁺ -lymphocytes are dependent on the intensity of endurance exercises and precise definition of the individual workload is important. The increase of granulocytes after exercise is partly due to increased levels of cortisol. Increased cell numbers of lymphocytes, especially CD16⁺ -cells, did not correlate to increased levels of catecholamines.

Key words

Endurance exercise - lymphocyte subpopulations - natural killer cells - catecholamines - cortisol