The effect of aerobic exercise on neutrophil functions.
OBJECTIVE
Intense exercise bouts are associated with a reduction of immune function and increased susceptibility to infections. Neutrophils act as a first line of defense to eliminate infectious agents and are also involved in muscle tissue inflammatory response to exercise. Intensive exercise suppresses several neutrophil functions including chemotaxis. The study investigates the pathophysiological mechanisms of impaired chemotaxis after submaximal aerobic exercise.


METHODS
Twenty-three healthy physically active adult males were tested before and 24 h after 30 min of treadmill running at 75% VO2max. N-formyl-Met-Leu-Phe (fMLP)-stimulated neutrophil migration, polarization, adherence, expression of adhesion molecules (CD11b/CD18), and chemotactic receptor (C5aR) were assessed preexercise and postexercise.


RESULTS
Neutrophil chemotaxis and polarization were found to be impaired 24 h postexercise. Adherence was impaired 24 h postexercise as well, but the expression of the adhesion molecule CD11b/CD18 was not affected. Further, the availability of the C5aR was found to be unaffected 24 h postaerobic exercise.


CONCLUSIONS
The pathophysiological mechanism of the impaired chemotaxis is likely related to the impaired postexercise neutrophil adherence and polarization but not to changes in the chemotactic receptor availability.
Gavrieli
Ronit
R
Department of Pediatrics and The Laboratory for Leukocyte Function, Meir Medical Center, Kfar Saba, Israel.
Ashlagi-Amiri
Tamar
T
Eliakim
Alon
A
Nemet
Dan
D
Zigel
Levana
L
Berger-Achituv
Sivan
S
Falk
Bareket
B
Wolach
Baruch
B
D000293:Adolescent; D000328:Adult; D039481:CD11b Antigen / Q000378:metabolism; D018821:CD18 Antigens / Q000378:metabolism; D002634:Chemotaxis, Leukocyte / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D009132:Muscles / Q000276:immunology / Q000378:metabolism; D009504:Neutrophils / Q000378:metabolism*; D044087:Receptor, Anaphylatoxin C5a; D011951:Receptors, Complement / Q000378:metabolism; D055815:Young Adult
C488033:C5AR1 protein, human; D039481:CD11b Antigen; D018821:CD18 Antigens; C509295:ITGAM protein, human; D044087:Receptor, Anaphylatoxin C5a; D011951:Receptors, Complement