低强度激光对6周递增负荷训练大鼠上呼吸道黏膜免疫机能的影响

The Effect of Low Power Laser on Mucosal Immune Function of upper respiratory tract in Rats during 6-week Incremental Training

目的:长期或一次性大强度运动引发的黏膜免疫抑制,与运动员集训和比赛期间的上呼吸道感染高发密切相关。以6周递增负荷训练诱导大鼠运动性免疫抑制,以不同剂量的低强度激光为干预手段,探讨低强度激光对大负荷训练机体上呼吸道黏膜免疫机能的保护作用。方法:8周龄雄性SD大鼠104只随机分为4组:安静对照组、运动训练组、运动与小剂量激光干预组、运动与大剂量激光干预组。运动各组进行递增负荷跑台训练,每天30 min,每周6天,共6周(第1周速度10 m/min;第2周速度20 m/min;第3周起每周速度递增5 m/min,至第6周为40 m/min)。激光干预组采用氦氖激光鼻腔外照射,1次/训练日,2 min/次。照射功率小剂量组1mw(6.8J/cm2),大剂量组2mw(13.6 J/cm2)。分别于训练前及第2、4、6周末,采集鼻腔冲洗液测sIgA,摘取鼻黏膜组织进行形态学结构评分和免疫组化法测CD4^+和CD8^+表达量。结果:1)6周递增负荷训练期间,大鼠鼻黏膜免疫功能显著下降。鼻黏膜结构进行性破坏。训练6周末时,鼻黏膜病理评分显著提高,CD4^+/CD8^+比值和s Ig A分泌量明显降低。2)小剂量低强度激光鼻部照射在训练的中后期可显著改善sIgA、CD4+与CD8+及其比值,以及鼻黏膜结构。3)大剂量激光的干预效果随照射疗程的延长呈下降的趋势。结论:6周递增负荷训练可导致大鼠鼻黏膜免疫功能发生明显抑制,鼻黏膜结构进行性破坏,鼻粘膜的体液和细胞免疫功能下降或紊乱。小剂量的低强度激光可明显改善鼻黏膜免疫功能。

PURPOSE:Nasal mucosal immune suppression,induced by long-term high-intensity training,could lead to an increasing risk of upper respiratory tract infections.This study aimed to examine the effect of laser irradiation on nasal mucosa structure and its immune function.METHODS:104 male Sprague Dawley rats(aged 8 weeks)were randomly divided into 4 groups:Control(C),Exercise(E),Exercise+Low power laser(E+LL,1 mw,6.8 J/cm2),and Exercise+High power laser(E+HL,2 mw,13.6 J/cm2).The rats in all Exercise-related groups performed an incremental treadmill exercise protocol:30 min/day,6 days/week,6 weeks;10 m/min velocity in 1st week,20 m/min in 2nd week,with 5 m/min/week increment for the following weeks.The laser treatments were He-Ne laser(2 h after exercise,2 min)at two irradiation point(each side of the nasal ala).Samples of all groups were collected in the beginning of training,as well as in the end of week 2nd,week 4th and week 6th respectively.Nasal mucosal structure were observed by HE staining,sIgA concentration of nasopharyngeal washings were examined by ELISA,and the expression of CD8+and CD4+T lymphocytes of nasal mucosa were analyzed by immunohistochemistry.RESULTS:1)Following changes(p<0.01)occurred in E group during 6 weeks:seriously damaged mucosa structure,gradually decline of sIgA level and ratio of CD4+/CD8+were observed in nasal mucosa.2)Compared with E group,the structure of nasal mucosa obviously improved,and the sIgA concentration,CD4+cells,and the ratio of CD4+/CD8+of nasal mucosa markedly increased in E+LL group.3)The E+HL group did not show significant improvement as those as EL group(p>0.05).CONCLUSION:Long-term high-intensity exercise training would lead to destruction of nasal mucosa structure and the declining of nasal immune function.Low power laser irradiation has a protective effect on nasal mucosa immune function.