Bronchial epithelial damage after a half-marathon in nonasthmatic amateur runners.
High neutrophil counts in induced sputum have been found in nonasthmatic amateur runners at rest and after a marathon, but the pathogenesis of airway neutrophilia in athletes is still poorly understood. Bronchial epithelial damage may occur during intense exercise, as suggested by investigations conducted in endurance-trained mice and competitive human athletes studied under resting conditions. To gain further information on airway changes acutely induced by exercise, airway cell composition, apoptosis, IL-8 concentration in induced sputum, and serum CC-16 level were measured in 15 male amateur runners at rest (baseline) and shortly after a half-marathon. Different from results obtained after a marathon, neutrophil absolute counts were unchanged, whereas bronchial epithelial cell absolute counts and their apoptosis increased significantly (P < 0.01). IL-8 in induced sputum supernatants almost doubled postrace compared with baseline (P < 0.01) and correlated positively with bronchial epithelial cell absolute counts (R(2) = 0.373, P < 0.01). Serum CC-16 significantly increased after all races (P < 0.01). These data show mild bronchial epithelial cell injury acutely induced by intense endurance exercise in humans, extending to large airways the data obtained in peripheral airways of endurance-trained mice. Therefore, neutrophil influx into the airways of athletes may be secondary to bronchial epithelial damage associated with intense exercise.
Chimenti
Laura
L
Dept. Biomedico Di Medicina Interna & Specialistica, Section of Pneumology, Univ. of Palermo, Via Trabucco 180, 90146 Palermo, Italy. laurachimenti@yahoo.it
Morici
Giuseppe
G
Paternò
Alessandra
A
Santagata
Roberta
R
Bonanno
Anna
A
Profita
Mirella
M
Riccobono
Loredana
L
Bellia
Vincenzo
V
Bonsignore
Maria R
MR
D000393:Air Pollutants / Q000032:analysis; D001980:Bronchi / Q000473:pathology*; D016535:Bronchial Hyperreactivity / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D007958:Leukocyte Count; D008297:Male; D009504:Neutrophils; D010807:Physical Endurance; D012420:Running; D013183:Sputum / Q000166:cytology; D014598:Uteroglobin / Q000378:metabolism
D000393:Air Pollutants; D016209:Interleukin-8; C556389:SCGB1A1 protein, human; C556390:Scgb1a1 protein, mouse; D014598:Uteroglobin