| （1.School of Physical Education，Jinan University，Guangzhou 510032，China；2.China Institute of Sport Science，Beijing 100061，China；3.School of Physical Education，South China Normal University，Guangzhou 510006，China) Abstract: In order to probe into low-power laser’s function on regulating lung tissue inflammation caused by exer-cise-induced immunosuppression, the authors divided 104 8-week old male SD rats randomly into a calm control group, an exercise training group, a small-dose low-power laser + exercise group, and a big-dose low-power laser + exercise group. The rats in the exercise groups carried out treadmill training for 6 weeks continuously, 30min/time, 1 time/day, 6 days/week. The authors used incremental load intensities (treadmill speed: 10m/min in week 1, 20m/min in week 2, then increased incrementally by 5m/min per week, starting from week 3, to 40m/min in week 6). Laser intervention used was He-Ne laser nasal external irradiation (1 time/day on training days, 2min/time). The irradiation power was 1mW (6.8 J/cm2) for the small-dose group, 2mW (13.6 J/cm2) for the big-dose group. The authors took samples respectively before training and at the ends of weeks 2, 4 and 6, measured the contents of sIgA, CRP, IL-4, IL-10, TNF-α and ICAM-1 in the bronchoalveolar lavage fluid, analyzed the expressions of posi-tive proteins CD4+ and CD8+ in the lung tissues, and carried out histomorphological observation on the lungs, and revealed the following findings: 1) during the 6-week incremental load training period, in the rats’ lungs, pro-inflammation cytokines TNF-α and ICAM-1 increased significantly, anti-inflammation cytokines IL-4 and IL-10 as well as sIgA and the ratio of CD4+ to CD8+ decreased significantly; the lung tissues showed local breeding, pus exudation, and gradually worsening inflammatory cell infiltration; 2) small-dose low-power laser irradiation can significantly slow the said changes of the exercise rats’ lung tissues, its effects on anti-inflammation cytokines and morphology were especially significant; while the effect of big-dose low-power laser intervention showed a trend of decreasing as the irradiation process extended. The said findings indicate the followings: small-dose low-power la-ser nasal irradiation can significantly promote the improvement of immune function and lung tissue inflammation reaction of the rats carrying out 6-week incremental load training, its regulating process is mainly to promote the balance between pro-inflammation cytokines and anti-inflammation cytokines by up-regulating the synthesis of anti-inflammation cytokines.
Key words: sports medicine；exercise-induced immunosuppression；low-power laser；lung；cytokine；rat |
