Abstract 13270: Acute High-Intensity Exercise Releases Myeloperoxidase and Pentraxin3 From Peripheral Neutrophils in Healthy Subjects
Background: Aerobic exercise training decreases arterial stiffness, while high-intensity resistance training increases arterial stiffness. Myeloperoxidase (MPO) is abundantly stored in neutrophils as pentraxin-3 (PTX3), an acute-phase protein that belongs to the family of the PTX, and produces the powerful oxidant hypochlorous acid, a key contributor to the oxygen-dependent microbicidal activity of phagocytes. On the other hand, excessive generation of MPO-derived oxidants has been linked to tissue damage in many diseases, especially those characterized by acute or chronic inflammation. We investigated the effects of several types of acute exercise on MPO and PTX3 in healthy subjects.
Methods: Nine healthy male subjects (41 ± 3 years old) participated. Each subject performed three types of exercise; ergometer exercise at 70% workload of anaerobic threshold (AT) for 30 min (70% AT exercise), peak ergometer exercise (peak EX, 20 watt increase/min until fatigue) and resistance exercises of 70% 1 RM (70% RE) until exhaustion. We measured plasma PTX3, MPO, lactate, noradrenaline (NOR), WBC, and interleukin-6 (IL-6). The effects of exercise on PTX3 and MPO in neutrophils were also investigated, by using flow cytometry analysis.
Results: Both MPO and PTX3 significantly increased immediately after 70% RE and peak EX, while they did not increase after 70% AT exercise. The exercise-induced fold increase in MPO and PTX3 relative to the resting level was positively correlated with the changes in WBC, NOR, and lactate. The exercise-induced fold increase in MPO and PTX3 was not significantly correlated with that in IL-6. Neutrophils isolated immediately after 70% RE, but not 70% AT exercise, exhibited lower mean fluorescence for PTX3 and MPO than those from pre-exercise blood.
Conclusions: These results show that high-intensity exercise releases PTX3, an acute phase of protein, and MPO from peripheral neutrophils in healthy subjects. The release of MPO may induce oxidative damage including endothelial dysfunction, and then the changes of vascular properties such as arterial stiffness reported in high-intensity resistance training.
- © 2010 by American Heart Association, Inc.