The response of the novel pro-inflammatory molecules S100A8/A9 to exercise.

Exercise shares many similarities with the acute phase response of inflammatory diseases. Recently, elevated serum levels of the novel pro-inflammatory molecules of the S100 protein family, S100A8 and S100A9, have been associated with various inflammatory diseases. The present study was conducted to assess their potential roles as inflammatory markers in monitoring the exercise-induced immune response. Seventeen male subjects of different training status performed a marathon run. Furthermore 13 subjects (10 male, 3 female) performed three different treadmill tests: strenuous (STE), moderate (MTE), and downhill (DTE). S100A8/A9 complexes were measured by ELISA, while white blood cell count (WBC) and C-reactive protein (CRP) were used as markers of the inflammatory response. Serum creatine kinase (CK) concentration was determined as a marker for muscle damage. After marathon S100A8/A9 increased dramatically during the early post-exercise period and returned to resting levels one day after the run. A similar pattern was found for WBC, while CK and CRP reached their maximum on the day after the run. Moreover, S100A8/A9 release was higher in the subgroup of well-trained athletes. The kinetic of the S100A8/A9 release after the treadmill tests depended on exercise intensity and was prolonged after eccentric exercise. In summary, the present results indicate that the novel pro-inflammatory molecules S100A8/A9 are very early and sensitive markers of the exercise-induced inflammatory response. Further investigations are necessary to evaluate the applicability of S100A8/A9 for monitoring the training process and to elucidate the dependence on training status.