Protective effects of aerobic exercise on acute lung injury induced by LPS in mice.
BACKGROUND
The regular practice of physical exercise has been associated with beneficial effects on various pulmonary conditions. We investigated the mechanisms involved in the protective effect of exercise in a model of lipopolysaccharide (LPS)-induced acute lung injury (ALI).


METHODS
Mice were divided into four groups: Control (CTR), Exercise (Exe), LPS, and Exercise + LPS (Exe + LPS). Exercised mice were trained using low intensity daily exercise for five weeks. LPS and Exe + LPS mice received 200 µg of LPS intratracheally 48 hours after the last physical test. We measured exhaled nitric oxide (eNO); respiratory mechanics; neutrophil density in lung tissue; protein leakage; bronchoalveolar lavage fluid (BALF) cell counts; cytokine levels in BALF, plasma and lung tissue; antioxidant activity in lung tissue; and tissue expression of glucocorticoid receptors (Gre).


RESULTS
LPS instillation resulted in increased eNO, neutrophils in BALF and tissue, pulmonary resistance and elastance, protein leakage, TNF-alpha in lung tissue, plasma levels of IL-6 and IL-10, and IL-1beta, IL-6 and KC levels in BALF compared to CTR (P ≤0.02). Aerobic exercise resulted in decreases in eNO levels, neutrophil density and TNF-alpha expression in lung tissue, pulmonary resistance and elastance, and increased the levels of IL-6, IL-10, superoxide dismutase (SOD-2) and Gre in lung tissue and IL-1beta in BALF compared to the LPS group (P ≤0.04).


CONCLUSIONS
Aerobic exercise plays important roles in protecting the lungs from the inflammatory effects of LPS-induced ALI. The effects of exercise are mainly mediated by the expression of anti-inflammatory cytokines and antioxidants, suggesting that exercise can modulate the inflammatory-anti-inflammatory and the oxidative-antioxidative balance in the early phase of ALI.
Cintia Tokio
CT
Reis Gonçalves
Carlos Gustavo
CG
Reis Gonçalves
Francine Maria
FM
de Almeida
Fernanda Degobi Tenório Quirino dos Santos
FD
Lopes
Ana Carolina Cardoso
AC
dos Santos Durão
Fabiana Almeida
FA
dos Santos
Luiz Fernando Ferraz
LF
da Silva
Tania
T
Marcourakis
Hugo C
HC
Castro-Faria-Neto
Rodolfo de Paula
RP
Vieira
Marisa
M
Dolhnikoff
D055371:Acute Lung Injury / Q000209:etiology / Q000517:prevention & control*; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid; D002452:Cell Count; D004926:Escherichia coli; D007378:Interleukins / Q000378:metabolism; D008070:Lipopolysaccharides / Q000009:adverse effects*; D008168:Lung / Q000378:metabolism / Q000502:physiology; D008807:Mice, Inbred BALB C; D023421:Models, Animal; D009504:Neutrophils / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D010805:Physical Conditioning, Animal; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D000099156:Superoxide Dismutase 2
D007378:Interleukins; D008070:Lipopolysaccharides; D009569:Nitric Oxide; D011965:Receptors, Glucocorticoid; D013482:Superoxide Dismutase; D014409:Tumor Necrosis Factor-alpha; D000099156:Superoxide Dismutase 2